Devices, circuits and equipment for load switching for protecting controlled loads

Abstract

The present application relates to a device, a circuit and a device for load switching for protecting a controlled load. The device comprises: a plurality of load switches, including at least a first and a second load switch, which are respectively connected in series with the first and second controlled loads to form first and second controlled load branches in parallel, each load switch is turned on when the switch control end is in a first voltage / current interval and is disconnected when the switch control end is in a second voltage / current interval; a signal control module, including a signal control element, the signal control element switches the connection between the switch control ends of the first and second load switches, and the signal control element makes the corresponding switch control end in the second voltage / current interval when connected to the switch control end and makes the corresponding switch control end in the first voltage / current interval when disconnected from the switch control end.

Description

Technical Field

[0001] The present application relates to the field of circuit control, and in particular to a device and a circuit for protecting a controlled load when switching between multiple loads in a circuit, and a device for load switching comprising the circuit. Background Art

[0002] In the current technology, there are cases where a circuit has multiple loads and different loads in the multiple loads are switched on under different conditions. For example, when the load is an LED, there is an LED product that switches between multiple LED loads to turn on different LED loads. For example, in a device such as a printer, a switching circuit that switches between various buttons needs to be provided in the device.

[0003] In existing multi-channel load circuits, when switching the loads, for example, when switching from one channel of load to another channel of load, the corresponding switch first switches from a closed state connected to the load to an open state. At this time, an overvoltage condition will be generated in the circuit due to the formation of an open circuit; and when the switch is switched from an open state to a closed state connected to another channel of load, the switching from the open circuit to the open circuit will generate a momentary high pulse current in the circuit. Overvoltage and high pulse current will damage the loads in the circuit. In the case where the load is an LED, it is easy to damage the LED product. Figure 1 As shown, Figure 1 (a) shows an LED circuit with two LED loads connected in parallel, wherein the switch is connected to one of the LED loads by switching the connection between contacts A and B. When the switch is switched from an open circuit state to a connection with contact A or B, a transient high pulse current is detected in the circuit, such as Figure 1 As shown in the solid line box in (b), the measured pulse current is as high as 726mA, while the current in the circuit is only 112mA when the switch is stably connected to contact A or B. This high pulse current can easily damage the LED load in the circuit.

[0004] At present, there is a technology that uses a buffer circuit to alleviate the overvoltage generated when switching loads, but the overvoltage cannot be eliminated, and the high pulse current generated during switching still exists. There is a technology that suppresses the overvoltage and high pulse current generated when switching by setting the opening and closing time of the switch logically, but this technology requires complex logic settings for the circuit, making the circuit structure complex and increasing the cost. It is expensive, affects other devices in the circuit, and is difficult to eliminate noise under high voltage. Summary of the invention

[0005] The embodiments of the present application provide a device and a circuit for protecting a controlled load and a device for load switching, so as to at least solve the problems of overvoltage and high pulse current generated when switching loads in the prior art.

[0006] According to one aspect of an embodiment of the present application, a device for protecting a controlled load is provided, comprising: a plurality of load switches, including at least a first load switch and a second load switch, the first load switch being connected in series with the first controlled load to form a first controlled load branch, the second load switch being connected in series with the second controlled load to form a second controlled load branch, the first controlled load branch being connected in parallel with the second controlled load branch, each of the first load switch and the second load switch comprising a switch control end and being turned on when the potential / current of the corresponding switch control end is in a first voltage / current interval and being turned off when the potential / current of the corresponding switch control end is in a second voltage / current interval; a signal control module, comprising a signal control element, wherein one end of the signal control element is switched between the switch control end of the first load switch and the switch control end of the second load switch, and one end of the signal control element makes the potential / current of the corresponding switch control end in the second voltage / current interval when connected to the switch control end of any one of the first load switch and the second load switch and makes the potential / current of the corresponding switch control end in the first voltage / current interval when disconnected from the switch control end of any one of the first load switch and the second load switch.

[0007] In this way, when the signal control element is connected to the switch control end of the first load switch, the first load switch is disconnected, thereby disconnecting the first controlled load branch; when the signal control element is disconnected from the switch control end of the first load switch, the first load switch is turned on, thereby turning on the first controlled load branch. Correspondingly, when the signal control element is connected to the switch control end of the second load switch, the second load switch is disconnected, thereby disconnecting the second controlled load branch; when the signal control element is disconnected from the switch control end of the second load switch, the second load switch is turned on, thereby turning on the second controlled load branch. Therefore, when the signal control module performs a disconnection and reconnection switching operation between the first controlled load branch and the second controlled load branch of the circuit, the circuit state first changes from one branch being turned on to both the first controlled load branch and the second controlled load branch being turned on, and then changes from both branches being turned on to the other branch being turned on.

[0008] With the above-mentioned device for protecting the controlled load, since the signal control element switches the connection between the switch control terminal of the first load switch and the switch control terminal of the second load switch, at least one controlled load branch is always in the on state during the switching process of the controlled load branch. Therefore, the circuit open state in which all controlled load branches are disconnected from the power supply during the switching process of the conducting branch is eliminated, thereby avoiding the overvoltage generated from the on state to the open state and the high pulse current generated from the open state to the on state, thereby protecting the controlled load in the circuit from damage by the overvoltage and the pulse current.

[0009] In this way, the overvoltage and pulse current generated by the circuit during the switching process are eliminated, so there is no need to use additional over-voltage protection (OVP) and pulse current suppression measures as in the prior art, which simplifies the circuit structure and reduces costs.

[0010] In an illustrative embodiment of a device for protecting a controlled load, the signal control module also includes a voltage control loop, the voltage control loop includes at least a first voltage branch and a second voltage branch connected in parallel, each of the first voltage branch and the second voltage branch is provided with a power supply end load having one end connected to the power supply end of the voltage control loop, the other end of the power supply end load in the first voltage branch is connected to a first connection point, the other end of the power supply end load in the second voltage branch is connected to a second connection point, the first connection point is connected to a switch control end of a first load switch, and the second connection point is connected to a switch control end of a second load switch, wherein the end of the signal control element switches the connection between the switch control end of the first load switch and the switch control end of the second load switch by switching the connection between the first connection point and the second connection point.

[0011] In this way, when the signal control element is connected to the first connection point, the first load switch is disconnected, thereby disconnecting the first controlled load branch; when the signal control element is disconnected from the first connection point, the first load switch is turned on, thereby turning on the first controlled load branch. Correspondingly, when the signal control element is connected to the second connection point, the second load switch is disconnected, thereby disconnecting the second controlled load branch; when the signal control element is disconnected from the second connection point, the second load switch is turned on, thereby turning on the second controlled load branch.

[0012] In an illustrative embodiment of the device for protecting a controlled load, a grounded load is further provided in each of the first voltage branch and the second voltage branch, and the first connection point and the second connection point are respectively grounded through the grounded load.

[0013] In this way, the potential of each of the first connection point and the second connection point is in a voltage / current interval when connected to the signal control element, and the potential of each of the first connection point and the second connection point is the divided potential of the power supply voltage borne by the grounded load when disconnected from the signal control element. By appropriately setting the values ​​of the power supply voltage, the power supply end load and the grounded load in the voltage branch, the potential of each of the first connection point and the second connection point is in the second voltage / current interval that causes the load switch to be disconnected when connected to the signal control element, and the potential of each of the first connection point and the second connection point is in the first voltage / current interval that causes the load switch to be turned on when disconnected from the signal control element, so that the corresponding load switch of each of the first connection point and the second connection point is turned off when connected to the signal control element, and the corresponding load switch of each of the first connection point and the second connection point is turned on when disconnected from the signal control element.

[0014] In an illustrative embodiment of a device for protecting a controlled load, a signal control element includes: a first voltage-controlled switch connected in parallel with a grounded load in a first voltage branch; a second voltage-controlled switch connected in parallel with a grounded load in a second voltage branch; and a signal control unit, one end of which is connected to a power supply end of a voltage control loop, wherein the other end of the signal control unit connects the signal control element to a first connection point when connected to a switch control end of the first voltage-controlled switch, and the other end of the signal control unit connects the signal control element to a second connection point when connected to a switch control end of the second voltage-controlled switch.

[0015] In this way, it is possible to realize that the signal control element switches the connection between the first connection point and the second connection point.

[0016] In an exemplary embodiment of the device for protecting a controlled load, a first voltage branch is formed by connecting a power supply end load and a signal control element in series, and a second voltage branch is formed by connecting a power supply end load and a signal control element in series.

[0017] In this way, the potential of each of the first connection point and the second connection point is in a voltage / current interval when connected to the signal control element, and the potential of each of the first connection point and the second connection point is in the power supply potential of the voltage control loop when disconnected from the signal control element, because the voltage branch corresponding to the connection point is open when the connection point is disconnected from the signal control element. Therefore, by appropriately setting the value of the power supply voltage and the load at the power supply end in the voltage branch, the potential of each of the first connection point and the second connection point is in the second voltage / current interval that causes the load switch to be disconnected when connected to the signal control element, and the potential of each of the first connection point and the second connection point is in the first voltage / current interval that causes the load switch to be turned on when disconnected from the signal control element, and it is also possible to achieve that the corresponding load switch of each of the first connection point and the second connection point is turned off when connected to the signal control element, and the corresponding load switch of each of the first connection point and the second connection point is turned on when disconnected from the signal control element.

[0018] In an illustrative embodiment of a device for protecting a controlled load, each of the first load switch and the second load switch includes a metal oxide semiconductor field effect transistor (MOS tube), and the switch control terminal of each of the first load switch and the second load switch is the gate of the MOS tube; or each of the first load switch and the second load switch includes a triode, and the switch control terminal of each of the first load switch and the second load switch is the base of the triode.

[0019] In this way, using a MOS tube or a transistor as a load switch can achieve the load switch being turned on when the potential / current at the switch control end of the load switch is in a first voltage / current interval and the load switch being turned off when the potential / current at the switch control end is in a second voltage / current interval.

[0020] In an exemplary embodiment of the device for protecting a controlled load, each of the first load switch and the second load switch further includes any one of a photocoupler, a relay, and a thyristor.

[0021] In this way, a combination of any one of a MOS tube or a triode and any one of a photocoupler, a relay, and a thyristor is used as a load switch, so that the load switch is turned on when the potential / current of the switch control end of the load switch is in a first voltage / current interval and the load switch is turned off when the potential / current of the switch control end is in a second voltage / current interval. At the same time, the advantages of electrical isolation and strong anti-interference ability of the photocoupler, the advantages of suitability for large loads and strong anti-interference ability of the relay, or the advantages of extremely fast response, strong overload resistance, no noise, and high efficiency of the thyristor are obtained.

[0022] In an illustrative embodiment of a device for protecting a controlled load, each of the first load switch and the second load switch includes an N-type MOS tube, the first voltage / current interval is a voltage interval greater than or equal to the turn-on voltage of the N-type MOS tube, and the second voltage / current interval is a voltage interval less than the turn-on voltage of the N-type MOS tube.

[0023] In this way, in the case where the load switch is an N-type MOS tube, by setting the first voltage / current interval to a voltage interval greater than or equal to the turn-on voltage of the N-type MOS tube and setting the second voltage / current interval to a voltage interval less than the turn-on voltage of the N-type MOS tube, it is possible to achieve that the load switch is turned on when the potential / current at the switch control end of the load switch is in the first voltage / current interval and the load switch is turned off when the potential / current at the switch control end is in the second voltage / current interval.

[0024] In addition, when the load switch is a P-type MOS tube or a transistor, or a combination of any one of a MOS tube and a transistor and any one of a photocoupler, a relay, and a thyristor, the first voltage / current interval and the second voltage / current interval are appropriately set according to the switching characteristics of the corresponding load switch.

[0025] In an illustrative embodiment of the device for protecting a controlled load, each of the first voltage-controlled switch and the second voltage-controlled switch includes a MOS tube, and the switch control terminal of each of the first voltage-controlled switch and the second voltage-controlled switch is the gate of the MOS tube; or each of the first voltage-controlled switch and the second voltage-controlled switch includes a triode, and the switch control terminal of each of the first voltage-controlled switch and the second voltage-controlled switch is the base of the triode.

[0026] In this way, using a MOS tube or a triode as a voltage-controlled switch, it is possible to achieve that when the other end of the signal control unit is connected to the switch control end of the first voltage-controlled switch, the signal control element is connected to the first connection point, and when the other end of the signal control unit is connected to the switch control end of the second voltage-controlled switch, the signal control element is connected to the second connection point. Thus, when the switch control unit is connected to the switch control end of the first or second voltage-controlled switch, the corresponding first or second controlled load branch is disconnected, and when the switch control unit is disconnected from the switch control end of the first or second voltage-controlled switch, the corresponding first or second controlled load branch is turned on.

[0027] According to another aspect of an embodiment of the present application, a circuit for protecting a controlled load is also provided, comprising: a plurality of controlled load branches connected in parallel, including at least a first controlled load branch and a second controlled load branch, wherein each controlled load branch is formed by connecting a corresponding controlled load and a load switch in series, and each load switch comprises a switch control end and is turned on when the potential / current of the switch control end is in a first voltage / current interval and is turned off when the potential / current of the switch control end is in a second voltage / current interval; a signal control module, comprising a signal control element, wherein one end of the signal control element is switched between the switch control end of a first load switch in the first controlled load branch and the switch control end of a second load switch in the second controlled load branch, and one end of the signal control element makes the potential / current of the corresponding switch control end in the second voltage / current interval when connected to the switch control end of any one of the first load switch and the second load switch, and makes the potential / current of the corresponding switch control end in the first voltage / current interval when disconnected from the switch control end of any one of the first load switch and the second load switch.

[0028] In this way, when the signal control element is connected to the switch control end of the first load switch, the first load switch is disconnected, thereby disconnecting the first controlled load branch; when the signal control element is disconnected from the switch control end of the first load switch, the first load switch is turned on, thereby turning on the first controlled load branch. Correspondingly, when the signal control element is connected to the switch control end of the second load switch, the second load switch is disconnected, thereby disconnecting the second controlled load branch; when the signal control element is disconnected from the switch control end of the second load switch, the second load switch is turned on, thereby turning on the second controlled load branch. Therefore, when the signal control module performs a disconnection and reconnection switching operation between the first controlled load branch and the second controlled load branch of the circuit, the circuit state first changes from one branch being turned on to both the first controlled load branch and the second controlled load branch being turned on, and then changes from both branches being turned on to the other branch being turned on.

[0029] By using the above circuit for protecting the controlled load, at least one controlled load branch is always in the on state during the switching process of the controlled load branch. Therefore, the circuit open state in which all controlled load branches are disconnected from the power supply during the switching process of the conducting branch is eliminated, thereby avoiding the overvoltage generated from the on state to the open state and the high pulse current generated from the open state to the on state, thereby protecting the controlled load in the circuit from damage by the overvoltage and pulse current. Therefore, there is no need to adopt additional overvoltage protection and pulse current suppression measures as in the prior art, so that the circuit structure is simplified and the cost is reduced.

[0030] In an illustrative embodiment of a circuit for protecting a controlled load, the signal control module also includes a voltage control loop, the voltage control loop includes at least a first voltage branch and a second voltage branch connected in parallel, each of the first voltage branch and the second voltage branch is provided with a power supply end load having one end connected to the power supply end of the voltage control loop, the other end of the power supply end load in the first voltage branch is connected to a first connection point, the other end of the power supply end load in the second voltage branch is connected to a second connection point, the first connection point is connected to a switch control end of a first load switch, and the second connection point is connected to a switch control end of a second load switch, wherein the end of the signal control element switches the connection between the switch control end of the first load switch and the switch control end of the second load switch by switching the connection between the first connection point and the second connection point.

[0031] In this way, when the signal control element is connected to the first connection point, the first load switch is disconnected, thereby disconnecting the first controlled load branch; when the signal control element is disconnected from the first connection point, the first load switch is turned on, thereby turning on the first controlled load branch. Correspondingly, when the signal control element is connected to the second connection point, the second load switch is disconnected, thereby disconnecting the second controlled load branch; when the signal control element is disconnected from the second connection point, the second load switch is turned on, thereby turning on the second controlled load branch.

[0032] In an illustrative embodiment of the circuit for protecting a controlled load, a grounded load is further provided in each of the first voltage branch and the second voltage branch, and the first connection point and the second connection point are respectively grounded through the grounded load.

[0033] In this way, the potential of each of the first connection point and the second connection point is in a voltage / current interval when connected to the signal control element, and the potential of each of the first connection point and the second connection point is the divided potential of the power supply voltage borne by the grounded load when disconnected from the signal control element. By appropriately setting the values ​​of the power supply voltage, the power supply end load and the grounded load in the voltage branch, the potential of each of the first connection point and the second connection point is in the second voltage / current interval that causes the load switch to be disconnected when connected to the signal control element, and the potential of each of the first connection point and the second connection point is in the first voltage / current interval that causes the load switch to be turned on when disconnected from the signal control element, so that the corresponding load switch of each of the first connection point and the second connection point is turned off when connected to the signal control element, and the corresponding load switch of each of the first connection point and the second connection point is turned on when disconnected from the signal control element.

[0034] In an illustrative embodiment of a circuit for protecting a controlled load, a signal control element includes: a first voltage-controlled switch connected in parallel with a grounded load in a first voltage branch; a second voltage-controlled switch connected in parallel with a grounded load in a second voltage branch; and a signal control unit, one end of which is connected to a power supply end of a voltage control loop, wherein the other end of the signal control unit connects the signal control element to a first connection point when connected to a switch control end of the first voltage-controlled switch, and connects the signal control element to a second connection point when the other end of the signal control unit is connected to a switch control end of the second voltage-controlled switch.

[0035] In this way, it is possible to realize that the signal control element switches the connection between the first connection point and the second connection point.

[0036] In an exemplary embodiment of the circuit for protecting a controlled load, a first voltage branch is formed by connecting a power supply end load and a signal control element in series, and a second voltage branch is formed by connecting a power supply end load and a signal control element in series.

[0037] In this way, the potential of each of the first connection point and the second connection point is in a voltage / current interval when connected to the signal control element, and the potential of each of the first connection point and the second connection point is in the power supply potential of the voltage control loop when disconnected from the signal control element, because the voltage branch corresponding to the connection point is open when the connection point is disconnected from the signal control element. Therefore, by appropriately setting the value of the power supply voltage and the load at the power supply end in the voltage branch, the potential of each of the first connection point and the second connection point is in the second voltage / current interval that causes the load switch to be disconnected when connected to the signal control element, and the potential of each of the first connection point and the second connection point is in the first voltage / current interval that causes the load switch to be turned on when disconnected from the signal control element, and it is also possible to achieve that the corresponding load switch of each of the first connection point and the second connection point is turned off when connected to the signal control element, and the corresponding load switch of each of the first connection point and the second connection point is turned on when disconnected from the signal control element.

[0038] In an illustrative embodiment of a circuit for protecting a controlled load, each of the first load switch and the second load switch includes a MOS tube, and the switch control terminal of each of the first load switch and the second load switch is the gate of the MOS tube; or each of the first load switch and the second load switch includes a transistor, and the switch control terminal of each of the first load switch and the second load switch is the base of the transistor.

[0039] In this way, using a MOS tube or a transistor as a load switch can achieve the load switch being turned on when the potential / current at the switch control end of the load switch is in a first voltage / current interval and the load switch being turned off when the potential / current at the switch control end is in a second voltage / current interval.

[0040] In an illustrative embodiment of the circuit for protecting a controlled load, each of the first load switch and the second load switch further includes any one of a photocoupler, a relay, and a thyristor.

[0041] In this way, a combination of any one of a MOS tube or a triode and any one of a photocoupler, a relay, and a thyristor is used as a load switch, so that the load switch is turned on when the potential / current of the switch control end of the load switch is in a first voltage / current interval and the load switch is turned off when the potential / current of the switch control end is in a second voltage / current interval. At the same time, the advantages of electrical isolation and strong anti-interference ability of the photocoupler, the advantages of suitability for large loads and strong anti-interference ability of the relay, or the advantages of extremely fast response, strong overload resistance, no noise, and high efficiency of the thyristor are obtained.

[0042] In an illustrative embodiment of a circuit for protecting a controlled load, each of the first load switch and the second load switch includes an N-type MOS tube, the first voltage / current interval is a voltage interval greater than or equal to the turn-on voltage of the N-type MOS tube, and the second voltage / current interval is a voltage interval less than the turn-on voltage of the N-type MOS tube.

[0043] In this way, in the case where the load switch is an N-type MOS tube, by setting the first voltage / current interval to a voltage interval greater than or equal to the turn-on voltage of the N-type MOS tube and setting the second voltage / current interval to a voltage interval less than the turn-on voltage of the N-type MOS tube, it is possible to achieve that the load switch is turned on when the potential / current at the switch control end of the load switch is in the first voltage / current interval and the load switch is turned off when the potential / current at the switch control end is in the second voltage / current interval.

[0044] In an illustrative embodiment of a circuit for protecting a controlled load, each of the first voltage-controlled switch and the second voltage-controlled switch includes a MOS tube, and the switch control terminal of each of the first voltage-controlled switch and the second voltage-controlled switch is the gate of the MOS tube; or each of the first voltage-controlled switch and the second voltage-controlled switch includes a triode, and the switch control terminal of each of the first voltage-controlled switch and the second voltage-controlled switch is the base of the triode.

[0045] In this way, using a MOS tube or a triode as a voltage-controlled switch, it is possible to achieve that when the other end of the signal control unit is connected to the switch control end of the first voltage-controlled switch, the signal control element is connected to the first connection point, and when the other end of the signal control unit is connected to the switch control end of the second voltage-controlled switch, the signal control element is connected to the second connection point. Thus, when the switch control unit is connected to the switch control end of the first or second voltage-controlled switch, the corresponding first or second controlled load branch is disconnected, and when the switch control unit is disconnected from the switch control end of the first or second voltage-controlled switch, the corresponding first or second controlled load branch is turned on.

[0046] According to another aspect of an embodiment of the present application, there is also provided a device for load switching, comprising: the above-mentioned circuit for protecting a controlled load; a logic control module, which receives a control signal and performs logic switch control on the circuit for protecting the controlled load in response to the control signal; and a switch control module, which provides a control signal to the logic control module instructing switching of a controlled load branch in the circuit.

[0047] In this way, it is possible to switch between multiple controlled load branches according to the control signal to turn on different controlled load branches, and at least one controlled load branch is always in the on state during the switching process of the controlled load branches. Therefore, the circuit is prevented from being in an open circuit state during the switching process, thereby avoiding the overvoltage generated from the on state to the open circuit state and the pulse current generated from the open circuit state to the on state.

[0048] According to the circuit for protecting the controlled load and the device for load switching according to the embodiment of the present application, another controlled load branch in addition to the first controlled load branch and the second controlled load branch may be provided with another controlled load in each of the other controlled load branches. As long as a corresponding signal control module including a signal control element is provided for each controlled load branch to form the above-mentioned device for protecting the controlled load, the circuit open state in the switch switching process in the circuit can be eliminated, thereby avoiding the overvoltage generated from the on state to the open state and the pulse current generated from the open state to the on state.

[0049] In the device and circuit for protecting the controlled load according to the embodiment of the present application, the signal control element may include a signal interface to receive a voltage / current signal output from a signal source. As long as the circuit is controlled so that the signal control element is connected to the switch control end of any one of the first load switch and the second load switch, the signal output from the signal source to the switch control end via the signal control element is a voltage / current signal in the second voltage / current interval, and the signal control element is disconnected from the switch control end of any one of the first load switch and the second load switch. The signal output from the signal source to the switch control end is a voltage / current signal in the first voltage / current interval, it is possible to achieve that when the signal control element is connected to the switch control end of the load switch, the corresponding controlled load branch is disconnected and when the signal control element is disconnected from the switch control end of the load switch, the corresponding controlled load branch is turned on. Thus, it is possible to achieve that at least one controlled load branch is always in the on state during the switching process of the controlled load branch, avoiding the occurrence of a circuit open state, thereby avoiding the overvoltage generated from the on state to the open state and the high pulse current generated from the open state to the on state.

[0050] In an embodiment of the present application, a technical solution is provided to eliminate the situation in which all controlled load branches are disconnected from the power supply during the switching process of the circuit by setting at least two parallel controlled load branches and making the signal control element switched between the switch control ends of the load switches of the at least two branches disconnect the corresponding controlled load branch when connected to a switch control end and turn on the corresponding controlled load branch when disconnected from the switch control end, so as to at least solve the technical problem of overvoltage generated from the on state to the open state and high pulse current generated from the open state to the on state when switching in a circuit containing multiple loads, thereby achieving the technical effect of protecting the controlled load in the circuit from the influence of overvoltage and high pulse current while simplifying the circuit structure and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0052] Figure 1 A circuit diagram of an LED circuit for switching connections between multiple LED loads in the prior art and a waveform diagram of the current in the circuit measured during the switching process;

[0053] Figure 2 is a circuit diagram of a circuit for protecting a controlled load according to an exemplary embodiment of the present application;

[0054] Figure 3 is a circuit diagram of a circuit for protecting a controlled load according to another exemplary embodiment of the present application;

[0055] Figure 4 is a circuit diagram of a circuit for protecting a controlled load according to another exemplary embodiment of the present application;

[0056] Figure 5 is a circuit diagram of a circuit for protecting a controlled load according to another exemplary embodiment of the present application;

[0057] Figure 6 is a circuit diagram of a circuit for protecting a controlled load according to another exemplary embodiment of the present application;

[0058] Figure 7 is a circuit diagram of a circuit for protecting a controlled load according to an exemplary embodiment of the present application and a waveform diagram of a current in the circuit measured during a switch switching process; and

[0059] Figure 8 is a block diagram of a device for load switching according to an embodiment of the present application.

[0060] Caption of the attached figure:

[0061] Cir: controlled load circuit

[0062] LED1: The first controlled load

[0063] LED2: Second controlled load

[0064] Q1: First load switch

[0065] Q2: Second load switch

[0066] SW: Signal control module

[0067] Sd: signal control element

[0068] Rs: power supply load

[0069] Rg: Ground load

[0070] C1: First connection point

[0071] C2: Second connection point

[0072] A, B: Contact

[0073] Q1': First voltage controlled switch

[0074] Q2': Second voltage controlled switch

[0075] Su: Signal control unit

[0076] OC1: Optocoupler

[0077] MOS1: MOS tube

[0078] MOS2: MOS tube

[0079] Relay RE1

[0080] Relay RE2 DETAILED DESCRIPTION

[0081] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0082] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or modules or units is not necessarily limited to those steps or modules or units clearly listed, but may include other steps or modules or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0083] According to an embodiment of the present application, a device for protecting a controlled load and a circuit for protecting a controlled load including the device are provided. Figure 2 is a circuit diagram of a circuit for protecting a controlled load according to an exemplary embodiment of the present application. Figure 2 As shown, the circuit for protecting the controlled load includes:

[0084] The controlled load circuit Cir includes a first controlled load branch and a second controlled load branch connected in parallel. The first controlled load branch includes a first controlled load LED1 and a first load switch Q1 connected in series, and the second controlled load branch includes a second controlled load LED2 and a second load switch Q2 connected in series. The controlled load circuit Cir supplies power to the first controlled load LED1 and the second controlled load LED2 by supplying power between LED+ and two LED-.

[0085] The signal control module SW includes a grounded signal control element Sd and a voltage control loop. The voltage control loop includes a first voltage branch and a second voltage branch connected in parallel, and each of the first voltage branch and the second voltage branch is provided with a power supply end load Rs having one end connected to the power supply end of the voltage control loop. The other end of the power supply end load Rs in the first voltage branch is connected to the first connection point C1, and the other end of the power supply end load Rs in the second voltage branch is connected to the second connection point C2, the first connection point C1 is connected to the switch control end of the first load switch Q1, and the second connection point C2 is connected to the switch control end of the second load switch Q2. The other end of the signal control element Sd can be switched between the first connection point C1 and the second connection point C2 by switching the connection between the contacts A and B. A grounded load Rg is also provided in each of the first voltage branch and the second voltage branch, and the first connection point C1 and the second connection point C2 are each grounded through the grounded load Rg. Each of the first connection point C1 and the second connection point C2 is at a zero potential when connected to the signal control element Sd, and is at a divided voltage potential borne by the ground load Rg when disconnected from the signal control element Sd.

[0086] The signal control module SW and the first load switch Q1 and the second load switch Q2 in the controlled load circuit Cir form a device for protecting the controlled load, which is also called a combination switch (SwitchBlock).

[0087] Figure 2 The first load switch Q1 and the second load switch Q2 shown in the figure are N-type MOS tubes. The N-type MOS tube is turned on when its gate voltage is greater than or equal to the conduction voltage, and is turned off when its gate voltage is less than the conduction voltage. By properly setting the values ​​of the power supply voltage V+, the power supply end load Rs and the ground load Rg in the voltage loop, so that the divided voltage potential borne by the ground load Rg is greater than or equal to the conduction voltage of the N-type MOS tube, it can be achieved that when the signal control element Sd is connected to the contact A, that is, when the signal control element Sd is connected to the first connection point C1, the first connection point C1 is at zero potential, so that the switch control end of the first load switch Q1 connected to the first connection point C1 is also at a zero potential less than the conduction voltage, so the first load switch Q1 is turned off, the first controlled load branch is in an open circuit state, and the first controlled load LED1 is disconnected from the power supply. At this time, the signal control element Sd is not connected to the contact B, so the potential at the second connection point C2 is the voltage-dividing potential borne by the grounded load Rg, that is, the switch control terminal of the second load switch Q2 connected to the second connection point C2 is also at the voltage-dividing potential borne by the grounded load Rg that is greater than or equal to the turn-on voltage, thereby turning on the second load switch Q2, that is, turning on the second controlled load branch.

[0088] When the signal control element Sd switches from being connected to contact point A to being connected to contact point B, the signal control element Sd is first disconnected from contact point A. At this time, neither the first connection point C1 nor the second connection point C2 is connected to the signal control element Sd. Therefore, the switch control terminals of the first load switch Q1 and the second load switch Q2 are respectively at the voltage-dividing potential borne by the ground load Rg, and the first load switch Q1 and the second load switch Q2 are both turned on, that is, the first controlled load LED1 and the second controlled load LED2 are both turned on. Then, the signal control element Sd switches from the disconnected state to being connected to contact point B. When the signal control element Sd is connected to contact point B, accordingly, the first controlled load branch is turned on and the second controlled load branch is disconnected from the power supply.

[0089] In this way, when the signal control element Sd performs a switching operation, the state of the circuit for protecting the controlled load changes from one controlled load branch being turned on to the first controlled load branch and the second controlled load branch being turned on, and then from both controlled load branches being turned on to the other controlled load branch being turned on. Therefore, it is ensured that there is always a controlled load branch in the on state during the switching process, and the circuit open state during the switching process is eliminated, thereby avoiding the overvoltage generated from the on state to the open state and the pulse current generated from the open state to the on state, thereby protecting the controlled load in the circuit from damage by the overvoltage and the pulse current.

[0090] In addition, in this way, since the overvoltage and pulse current generated by the circuit during the switching of the signal control element are directly eliminated, there is no need to use additional overvoltage protection and pulse current suppression measures as in the prior art, which simplifies the circuit structure and reduces costs.

[0091] It should be noted that although Figure 2 In the exemplary embodiment, the first load switch Q1 and the second load switch Q2 are shown as MOS tubes, and the switch control terminals of the first load switch Q1 and the second load switch Q2 are respectively shown as gates of the corresponding MOS tubes, but those skilled in the art will understand that any switching device can be used as the first load switch and the second load switch, as long as the switching device is turned on when the potential / current of the switch control terminal is in the first voltage / current interval and is turned off when the potential / current of the switch control terminal is in the second voltage / current interval.

[0092] In another exemplary embodiment, the first load switch and the second load switch are triodes, and the switch control terminal is the base of the triode. When the base current of the triode is zero, the collector and emitter currents of the triode are both zero, and the triode is in a cut-off state, that is, a disconnected state. When the base current increases to a certain current, the collector and emitter currents of the triode are in a saturated state, that is, the triode is in a conducting state. In yet another exemplary embodiment, the first load switch and the second load switch are a combination of any one of a MOS tube and a triode and any one of a photocoupler, a relay, and a thyristor.

[0093] It should be noted that Figure 2 In the exemplary embodiment of the invention, the signal control element Sd is shown as a single-pole double-throw switch. However, those skilled in the art will appreciate that other switch forms capable of switching connections between contacts may also be used. In addition, in the case where the controlled load circuit Cir also includes additional controllable load branches, a single-pole triple-throw switch or the like may also be used.

[0094] Figure 3 is a circuit diagram of a circuit for protecting a controlled load according to another exemplary embodiment of the present application. Figure 3 The circuit shown for protecting the controlled load is similar to Figure 2 The circuit for protecting the controlled load shown includes the same controlled load circuit Cir and voltage control circuit. Figure 2 The embodiments shown in FIG. 1 are not described in detail here. Figure 3 As shown in Figure 2 The signal control element Sd shown is described differently from the signal control elements.

[0095] like Figure 3 The signal control element in the circuit for protecting the controlled load shown includes: a first voltage control switch Q1' connected in parallel with the grounded load Rg in the first voltage branch, a second voltage control switch Q2' connected in parallel with the grounded load Rg in the second voltage branch, and a signal control unit Su. One end of the signal control unit Su is connected to the power supply end of the voltage control loop, and the other end can switch between the switch control end of the first voltage control switch Q1' and the switch control end of the second voltage control switch Q2' by switching between contacts A and B. When the other end of the signal control unit Su is connected to contact A, that is, connected to the switch control end of the first voltage control switch Q1', the signal control element is connected to the first connection point C1; when the other end of the signal control unit Su is connected to contact B, that is, connected to the switch control end of the second voltage control switch Q2', the signal control element is connected to the second connection point C2.

[0096] In this way, the signal control element can also be switched between the first connection point and the second connection point, so that when the signal control element is connected to the contact point A or B, the corresponding first load switch Q1 or the second load switch Q2 is disconnected, thereby disconnecting the corresponding first controlled load LED1 or the second controlled load LED2; when the signal control element is disconnected from the contact point A or B, the corresponding first load switch Q1 or the second load switch Q2 is turned on, thereby turning on the corresponding first controlled load LED1 or the second controlled load LED2.

[0097] Therefore, when the signal control element performs a switching operation, the state of the circuit for protecting the controlled load changes from one controlled load branch being turned on to the first controlled load branch and the second controlled load branch being turned on, and then from both controlled load branches being turned on to the other controlled load branch being turned on. Therefore, the circuit open state during the switching process can also be eliminated, thereby avoiding the overvoltage generated from the on state to the open state and the pulse current generated from the open state to the on state.

[0098] It should be noted that Figure 3 In the exemplary embodiment, the first voltage control switch Q1' and the second voltage control switch Q2' are shown as MOS tubes, and the switch control terminal of the first voltage control switch Q1' and the switch control terminal of the second voltage control switch Q2' are shown as gates of MOS tubes. However, those skilled in the art will understand that other contactless switch devices such as triodes that can be controlled to be on and off by controlling voltage or current can also be used. Figure 3 In the exemplary embodiment of the present invention, the signal control unit Su is shown as a single-pole double-throw switch. However, those skilled in the art will appreciate that other switch forms capable of switching connections between contacts may also be used.

[0099] Figure 4 is a circuit diagram of a circuit for protecting a controlled load according to yet another exemplary embodiment of the present application. Figure 4 The circuit shown for protecting the controlled load is similar to Figure 2 The main difference between the circuits shown for protecting controlled loads is that Figure 4 In the circuit shown, each of the first voltage branch and the second voltage branch of the voltage control loop is formed by connecting the power supply end load Rs and the signal control element Sd in series; Figure 2 In the circuit shown, each of the first voltage branch and the second voltage branch of the voltage control loop is formed by a power supply end load Rs and a ground load Rg connected in series.

[0100] In this way, each of the first connection point C1 and the second connection point C2 is at zero potential when connected to the signal control element Sd, and each of the first connection point C1 and the second connection point C2 is at the power supply potential of the voltage control loop when disconnected from the signal control element Sd, because the voltage branch corresponding to the connection point is open when the connection point is disconnected from the signal control element Sd.

[0101] Therefore, it is also possible to realize that when the signal control element Sd performs a switching operation, the state of the circuit for protecting the controlled load changes from one controlled load branch being turned on to both the first controlled load branch and the second controlled load branch being turned on, and then from both controlled load branches being turned on to the other controlled load branch being turned on. In other words, during the switching process of the controlled load branch, there is always a controlled load branch in the on state, eliminating the circuit open state during the switching process, thereby avoiding the overvoltage generated from the on state to the open state and the pulse current generated from the open state to the on state.

[0102] Figure 4 The circuit shown for protecting the controlled load is similar to Figure 2 A further difference of the circuit shown for protecting a controlled load is that in Figure 4 In the circuit shown, the first controlled load and the second controlled load are both formed by connecting a plurality of LED units in series and parallel, and the voltage control loop and the controlled load loop share the same power supply.

[0103] In this way, the load on each controlled load branch can be expanded to meet various usage requirements, and a single common power supply can be used to simplify the circuit structure and reduce costs.

[0104] Figure 5 is a circuit diagram of a circuit for protecting a controlled load according to yet another exemplary embodiment of the present application. Figure 5 The circuit shown for protecting the controlled load is similar to Figure 2 The circuit for protecting the controlled load shown contains the same signal control module. The description of this module refers to Figure 2 The illustrated implementation will not be described in detail here. Figure 5 The circuit shown for protecting the controlled load is similar to Figure 2 The circuits shown for protecting a controlled load differ in the load switch used. Figure 2 The load switch is shown as a MOS tube, and Figure 5 The load switch is shown as a combination of a MOS tube and a photocoupler.

[0105] like Figure 5The first load switch in the circuit for protecting the controlled load shown includes a photocoupler OC1 and a MOS tube MOS1 connected in series. The gate of the MOS tube MOS1 serves as the switch control terminal of the first load switch, the primary side of the photocoupler OC1 is connected in series with the MOS tube MOS1, and the secondary side of the photocoupler OC1 is connected in series with the controlled load LED1. When the signal control element Sd is connected to the contact A, the first connection point C1 is at zero potential, so that the gate of the MOS tube MOS1 connected to the first connection point C1 is also at zero potential, so the MOS tube MOS1 is disconnected, and no current passes through the primary side of the photocoupler OC1, so the secondary side of the photocoupler OC1 is disconnected, that is, the first controlled load branch is disconnected. When the signal control element Sd is disconnected from the contact A, the first connection point C1 is at the divided voltage potential borne by the grounded load. By appropriately setting the power supply voltage on the voltage branch and the values ​​of the power supply end load and the grounded load, the divided voltage potential borne by the grounded load is greater than or equal to the conduction potential of the MOS tube MOS1. At this time, the MOS tube MOS1 is turned on, and a certain current passes through the primary side of the photocoupler OC1. By properly selecting the parameters of the photocoupler OC1, its secondary side is in saturation conduction at this time, that is, the first controlled load branch is turned on. In the same way, when the signal control element Sd is connected to the contact B, the MOS transistor MOS2 is disconnected, so that the second controlled load branch is disconnected, and when the signal control element Sd is disconnected from the contact B, the MOS transistor MOS2 is turned on, so that the second controlled load branch is turned on.

[0106] In this way, a combination of a MOS tube and a photocoupler is used as a load switch, which can realize that the load switch is turned on when the potential / current of the switch control end of the load switch is in a first voltage / current interval and the load switch is turned off when the potential / current of the switch control end is in a second voltage / current interval, while obtaining the advantages of electrical isolation and strong anti-interference ability of the photocoupler.

[0107] Figure 6 is a circuit diagram of a circuit for protecting a controlled load according to yet another exemplary embodiment of the present application. Figure 6 The circuit shown for protecting the controlled load is similar to Figure 2 The circuit for protecting the controlled load shown contains the same signal control module. The description of this module refers to Figure 2 The illustrated implementation will not be described in detail here. Figure 6 The circuit shown for protecting the controlled load is similar to Figure 2 The circuits shown for protecting a controlled load differ in the load switch used. Figure 2 The load switch is shown as a MOS tube, and Figure 6 The load switch is shown as a combination of a MOS tube and a relay.

[0108] like Figure 6 The first load switch in the circuit for protecting the controlled load shown includes a relay RE1 and a MOS transistor MOS1 connected in series. The gate of the MOS transistor MOS1 serves as the switch control terminal of the first load switch, the input side of the relay RE1 is connected in series with the MOS transistor MOS1, and the output side of the relay RE1 is connected in series with the controlled load LED1. When the signal control element Sd is connected to the contact A, the first connection point C1 is at zero potential, so that the gate of the MOS transistor MOS1 connected to the first connection point C1 is also at zero potential, so the MOS transistor MOS1 is disconnected, no current flows through the input side coil of the relay RE1, so the static contact on the output side is also in a disconnected state, and the first controlled load branch is disconnected. When the signal control element Sd is disconnected from the contact A, the first connection point C1 is at the voltage-dividing potential borne by the grounded load. By appropriately setting the power supply voltage on the voltage branch and the values ​​of the power supply end load and the grounded load, the voltage-dividing potential borne by the grounded load is greater than or equal to the conduction potential of the MOS tube MOS1. At this time, the MOS tube MOS1 is turned on, and a certain current flows through the input side of the relay RE1. By appropriately setting the value of the current, the output side of the relay RE1 is turned on, that is, the first controlled load branch is turned on. In the same way, when the signal control element Sd is connected to the contact B, the static contact of the relay RE2 is disconnected, so that the second controlled load branch is disconnected, and when the signal control element Sd is disconnected from the contact B, the static contact of the relay RE2 is turned on, so that the second controlled load branch is turned on.

[0109] In this way, a combination of a MOS tube and a relay is used as a load switch, which can realize that the load switch is turned on when the potential / current of the switch control end of the load switch is in the first voltage / current interval and the load switch is turned off when the potential / current of the switch control end is in the second voltage / current interval, while obtaining the advantages of the relay's suitability for large loads and strong anti-interference ability.

[0110] In addition, those skilled in the art should understand that a combination of a MOS tube and a thyristor, a triode, or a combination of a triode and any one of a photocoupler, a relay, and a thyristor can also be used as a load switch, as long as the first voltage / current interval that turns on the load switch and the second voltage / current interval that turns off the load switch are appropriately set according to the switching characteristics of the corresponding load switch.

[0111] Figure 7 1 is a circuit diagram of a circuit for protecting a controlled load according to an exemplary embodiment of the present application and a waveform diagram of a current in the circuit measured during a switch switching process. Figure 7 (a) shows a circuit diagram of a circuit for protecting a controlled load according to an exemplary embodiment of the present application, Figure 7 The solid line box in (a) shows the Figure 1The difference between the circuit shown in (a) and Figure 7 (b) shows a waveform diagram of the current measured in the circuit during the switching process.

[0112] like Figure 7 As shown in (a), when the switch in the circuit is connected to contact A, the first controlled load LED1 corresponding to contact A is disconnected, and the second controlled load LED2 corresponding to contact B is turned on. When the switch in the circuit is connected to contact B, the second controlled load LED2 corresponding to contact B is disconnected, and the first controlled load LED1 corresponding to contact A is turned on. When the switch in the circuit is in the disconnected state, that is, it is neither connected to contact A nor to contact B, the first controlled load LED1 and the second controlled load LED2 are both turned on.

[0113] Figure 7 (b) shows a waveform diagram of the current in the circuit measured when the switch in the circuit is switched between contacts A and B. Figure 7 As can be seen from (b), when the switch switches between the open and closed states, the current in the circuit switches between 112mA and 100mA. Figure 1 Compared with (b), the high pulse current that appears in the circuit when the switch switches from open to closed is eliminated.

[0114] exist Figures 2 to 7 In the exemplary embodiments shown, the controlled loads are all shown as LEDs, but those skilled in the art should understand that the controlled loads herein are not limited to LEDs, but may be various loads that can operate in a power-on state.

[0115] Figure 8 is a block diagram of a device for load switching according to an embodiment of the present application. Figure 8 As shown, the equipment used for load switching includes:

[0116] A circuit for protecting a controlled load, comprising a plurality of controlled load branches and a signal control module, wherein a load switch for each controlled load is connected in series with each corresponding controlled load to form each controlled load branch, and the plurality of controlled load branches are connected in parallel, wherein a switch control end of each load switch is turned on when it is at a certain potential / current or a certain potential / current interval, and is turned off when it is at another potential / current or another potential / current interval, and the plurality of load switches and the signal control module form a combination switch;

[0117] A logic control module, which realizes the logic switch control of the combination switch; and

[0118] The switch control module realizes the switching of the control signal and provides the control signal to the logic control module.

[0119] In this way, the device for load switching includes at least two groups of controlled load branches. During the switching process through the switch control module, it is ensured that at least one controlled load branch remains conducting in any case, and all controlled loads will not be disconnected from the power supply. This is to prevent overvoltage and impact current from being generated during the switching process of the controlled load branches, so as to avoid damage to the controlled loads.

[0120] In this embodiment, the signal control module is included in the combination switch. The signal control module can be Figures 2 to 7 The signal control module SW in any of the exemplary embodiments shown.

[0121] In this embodiment, the switch control module provides a control signal to the logic control module to instruct the controlled load branch in the circuit to switch, so that one or more different controlled load branches are turned on. In response to the control signal, the logic control module performs logic switch control on the circuit for protecting the controlled load, so that the circuit on-off state is switched from the current one or more controlled load branches being turned on to the different one or more controlled load branches being turned on. In an exemplary embodiment, the logic controller is a micro control unit (MCU). In another exemplary embodiment, the logic controller is a control circuit composed of multiple MOS tubes.

[0122] In this embodiment, the device for load switching further includes a power supply for supplying power to the control module, the combination switch and the controlled load.

[0123] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic, for example, the division of the units or modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple units or modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0125] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A device for protecting a controlled load, characterized in that: include: A plurality of load switches, comprising at least a first load switch (Q1) and a second load switch (Q2), wherein the first load switch (Q1) is connected in series with a first controlled load (LED1) to form a first controlled load branch, and the second load switch (Q2) is connected in series with a second controlled load (LED2) to form a second controlled load branch, the first controlled load branch and the second controlled load branch are connected in parallel, and each of the first load switch (Q1) and the second load switch (Q2) comprises a switch control terminal and is turned on when the potential / current of the corresponding switch control terminal is in a first voltage / current interval and is turned off when the potential / current of the corresponding switch control terminal is in a second voltage / current interval; A signal control module (SW) comprises a signal control element (Sd), wherein one end of the signal control element (Sd) is switched between the switch control end of the first load switch (Q1) and the switch control end of the second load switch (Q2), and when the one end of the signal control element (Sd) is connected to the switch control end of any one of the first load switch (Q1) and the second load switch (Q2), the potential / current of the corresponding switch control end is in the second voltage / current interval, and when the one end of the signal control element (Sd) is disconnected from the switch control end of any one of the first load switch (Q1) and the second load switch (Q2), the potential / current of the corresponding switch control end is in the first voltage / current interval.

2. The device according to claim 1, characterized in that The signal control module also includes a voltage control loop, the voltage control loop includes at least a first voltage branch and a second voltage branch connected in parallel, each of the first voltage branch and the second voltage branch is provided with a power supply end load (Rs) having one end connected to the power supply end of the voltage control loop, the other end of the power supply end load (Rs) in the first voltage branch is connected to a first connection point (C1), the other end of the power supply end load (Rs) in the second voltage branch is connected to a second connection point (C2), the first connection point (C1) is connected to the switch control end of the first load switch (Q1), and the second connection point (C2) is connected to the switch control end of the second load switch (Q2), The one end of the signal control element (Sd) switches the connection between the switch control end of the first load switch (Q1) and the switch control end of the second load switch (Q2) by switching the connection between the first connection point (C1) and the second connection point (C2).

3. The device according to claim 2, characterized in that A ground load (Rg) is further provided in each of the first voltage branch and the second voltage branch, and the first connection point (C1) and the second connection point (C2) are each grounded through the ground load (Rg).

4. The device according to claim 3, characterized in that The signal control element (Sd) comprises: a first voltage-controlled switch (Q1') connected in parallel with the grounded load (Rg) in the first voltage branch, a second voltage controlled switch (Q2') connected in parallel with the grounded load (Rg) in the second voltage branch, and A signal control unit (Su), one end of which is connected to the power supply end of the voltage control loop, wherein the other end of the signal control unit (Su) connects the signal control element (Sd) to the first connection point (C1) when connected to the switch control end of the first voltage control switch (Q1'), and the other end of the signal control unit (Su) connects the signal control element (Sd) to the second connection point (C2) when connected to the switch control end of the second voltage control switch (Q2').

5. The device according to claim 2, characterized in that The first voltage branch is formed by connecting the power supply end load (Rs) and the signal control element (Sd) in series, and the second voltage branch is formed by connecting the power supply end load (Rs) and the signal control element (Sd) in series.

6. The device according to any one of claims 1 to 5, characterized in that Each of the first load switch (Q1) and the second load switch (Q2) includes a MOS tube, and the switch control end of each of the first load switch (Q1) and the second load switch (Q2) is a gate of the MOS tube; or each of the first load switch (Q1) and the second load switch (Q2) includes a triode, and the switch control end of each of the first load switch (Q1) and the second load switch (Q2) is a base of the triode.

7. The device according to any one of claims 1 to 5, characterized in that Each of the first load switch (Q1) and the second load switch (Q2) further includes any one of a photocoupler, a relay, and a thyristor.

8. The device according to claim 6, characterized in that Each of the first load switch (Q1) and the second load switch (Q2) includes an N-type MOS tube, the first voltage / current interval is a voltage interval greater than or equal to a turn-on voltage of the N-type MOS tube, and the second voltage / current interval is a voltage interval less than the turn-on voltage of the N-type MOS tube.

9. The device according to claim 4, characterized in that Each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') includes a MOS tube, and the switch control end of each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') is a gate of the MOS tube; or each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') includes a triode, and the switch control end of each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') is a base of the triode.

10. A circuit for protecting a controlled load, characterized in that: include: A plurality of parallel controlled load branches, including at least a first controlled load branch and a second controlled load branch, wherein each controlled load branch is formed by connecting a corresponding controlled load and a load switch in series, and each load switch includes a switch control terminal and is turned on when the potential / current of the switch control terminal is in a first voltage / current interval and is turned off when the potential / current of the switch control terminal is in a second voltage / current interval; A signal control module, comprising a signal control element (Sd), wherein one end of the signal control element (Sd) is switched between a switch control end of a first load switch (Q1) in the first controlled load branch and a switch control end of a second load switch (Q2) in the second controlled load branch, and when one end of the signal control element (Sd) is connected to the switch control end of any one of the first load switch (Q1) and the second load switch (Q2), the potential / current of the corresponding switch control end is in the second voltage / current interval, and when one end of the signal control element (Sd) is disconnected from the switch control end of any one of the first load switch (Q1) and the second load switch (Q2), the potential / current of the corresponding switch control end is in the first voltage / current interval.

11. The circuit according to claim 10, characterized in that The signal control module also includes a voltage control loop, the voltage control loop includes at least a first voltage branch and a second voltage branch connected in parallel, each of the first voltage branch and the second voltage branch is provided with a power supply end load (Rs) having one end connected to the power supply end of the voltage control loop, the other end of the power supply end load (Rs) in the first voltage branch is connected to a first connection point (C1), the other end of the power supply end load (Rs) in the second voltage branch is connected to a second connection point (C2), the first connection point (C1) is connected to the switch control end of the first load switch (Q1), and the second connection point (C2) is connected to the switch control end of the second load switch (Q2), The one end of the signal control element (Sd) switches the connection between the switch control end of the first load switch (Q1) and the switch control end of the second load switch (Q2) by switching the connection between the first connection point (C1) and the second connection point (C2).

12. The circuit according to claim 11, characterized in that A ground load (Rg) is further provided in each of the first voltage branch and the second voltage branch, and the first connection point (C1) and the second connection point (C2) are each grounded through the ground load (Rg).

13. The circuit according to claim 12, characterized in that The signal control element (Sd) comprises: a first voltage-controlled switch (Q1') connected in parallel with the grounded load (Rg) in the first voltage branch, a second voltage controlled switch (Q2') connected in parallel with the grounded load (Rg) in the second voltage branch, and A signal control unit (Su), one end of which is connected to the power supply end of the voltage control loop, wherein the other end of the signal control unit (Su) connects the signal control element (Sd) to the first connection point (C1) when connected to the switch control end of the first voltage control switch (Q1'), and the other end of the signal control unit (Su) connects the signal control element (Sd) to the second connection point (C2) when connected to the switch control end of the second voltage control switch (Q2').

14. The circuit according to claim 11, characterized in that The first voltage branch is formed by connecting the power supply end load (Rs) and the signal control element (Sd) in series, and the second voltage branch is formed by connecting the power supply end load (Rs) and the signal control element (Sd) in series.

15. The circuit according to any one of claims 10 to 14, characterized in that Each of the first load switch (Q1) and the second load switch (Q2) includes a MOS tube, and the switch control end of each of the first load switch (Q1) and the second load switch (Q2) is a gate of the MOS tube; or each of the first load switch (Q1) and the second load switch (Q2) includes a triode, and the switch control end of each of the first load switch (Q1) and the second load switch (Q2) is a base of the triode.

16. The circuit according to any one of claims 10 to 14, characterized in that Each of the first load switch (Q1) and the second load switch (Q2) further includes any one of a photocoupler, a relay, and a thyristor.

17. The circuit according to claim 15, characterized in that Each of the first load switch (Q1) and the second load switch (Q2) includes an N-type MOS tube, the first voltage / current interval is a voltage interval greater than or equal to a turn-on voltage of the N-type MOS tube, and the second voltage / current interval is a voltage interval less than the turn-on voltage of the N-type MOS tube.

18. The circuit according to claim 13, characterized in that Each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') includes a MOS tube, and the switch control end of each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') is a gate of the MOS tube; or each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') includes a triode, and the switch control end of each of the first voltage-controlled switch (Q1') and the second voltage-controlled switch (Q2') is a base of the triode.

19. A device for load switching, characterized in that: include: A circuit for protecting a controlled load according to any one of claims 10 to 18; A logic control module receives a control signal and performs logic switch control on the circuit for protecting the controlled load in response to the control signal; as well as The switch control module provides the control signal instructing the controlled load branch in the circuit to switch to the logic control module.

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