Control circuit with built-in load switch

Abstract

The utility model discloses a control circuit with a built-in load switch. The control circuit comprises a relay driving module, a forced closing locking circuit, a timing driving module and a first voltage stabilizing circuit. The relay driving module is respectively connected with the forced closing locking circuit, the timing driving module and the first voltage stabilizing circuit, and the forced closing locking circuit is connected with the timing driving module; the forced closing locking circuit is used for driving the relay driving module to control the load switch to perform forced closing operation in an abnormal state; and the timing driving module is used for generating a timing driving signal matched with the relay and acting on the relay driving module to regularly control the switching-on or switching-off operation of the load switch. According to the utility model, the technical problems of collective tripping of the user sides and how to drive the relay at regular time to control the closing and opening of the user sides in an abnormal state are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of built-in load switch control for instruments, in particular to a control circuit for a built-in load switch. Background Art

[0002] At present, existing load switch drive circuits are all based on single-chip microcomputer control and long-term continuous power supply to drive a coil to complete the closing and tripping actions. For example, the patent document with the application number CN20228373.X discloses a magnetic latching relay drive circuit, including: a micro control unit in a control module outputs a corresponding voltage signal according to a received configuration instruction. A comparison module receives the voltage signal through a general input / output interface of the control module, and outputs a corresponding control signal according to the comparison result between the voltage signal and a voltage reference signal. A drive module outputs a corresponding drive signal to the magnetic latching relay according to the control signal, that is, different drive signals are generated by different voltage signals to control the magnetic latching relay to enter different working states. The magnetic latching relay only needs to occupy a general input / output interface (GPIO) of a micro control unit (MCU) to realize the switching of different working states. This method can control more magnetic latching relays by a control module in an application scenario where multiple magnetic latching relays are required, but the signal comes from the control of the MCU and can only work when the MCU is running normally. When the MCU is abnormal or under external hacker attacks, abnormalities will occur, resulting in collective tripping of instruments, power outage at the client side and inability to recover. Therefore, there is an urgent need to propose a control circuit for a built-in load switch to solve the technical problems of collective tripping at the user end in abnormal states and how to drive the relay regularly to control the closing and opening of the user end. Summary of the Utility Model

[0003] The main object of the utility model is to propose a control circuit for a built-in load switch, aiming to solve the technical problems of collective tripping at the user end in abnormal states and how to drive the relay regularly to control the closing and opening of the user end.

[0004] To achieve the above object, the utility model provides a control circuit for a built-in load switch, wherein the control circuit for the built-in load switch includes:

[0005] A relay drive module, a forced closing locking circuit, a timing drive module, and a first voltage stabilizing circuit;

[0006] The relay drive module is respectively connected to the forced closing locking circuit, the timing drive module, and the first voltage stabilizing circuit, and the forced closing locking circuit is connected to the timing drive module;

[0007] The forced closing locking circuit is used to drive the relay driving module to control the load switch to perform a forced closing operation in an abnormal state; the timing driving module is used to generate a timing driving signal matching the relay and act on the relay driving module to control the opening or closing operation of the load switch at a fixed time.

[0008] One of the preferred solutions is that the relay driving module includes a relay driving chip U1;

[0009] Pin 1 of the relay driving chip U1 is connected to the timing driving module;

[0010] Pin 2 of the relay driving chip U1 is grounded;

[0011] Pin 3 of the relay driving chip U1 is connected to the forced closing locking circuit;

[0012] Pins 4 and 5 of the relay driving chip U1 are connected to the load switch through an induction coil;

[0013] Pin 6 of the relay driving chip U1 is connected to the power supply terminal.

[0014] One of the preferred solutions is that the forced closing locking circuit includes a first current limiting circuit, a clamping circuit and a DIP switch SW1;

[0015] One end of the first current limiting circuit is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, the other end of the first current limiting circuit is respectively connected to the clamping circuit and the relay driving module, the other end of the clamping circuit is respectively connected to the timing driving module and the DIP switch SW1, and the other end of the DIP switch SW1 is grounded.

[0016] One of the preferred solutions is that the first current limiting circuit includes a resistor R6; one end of the resistor R6 is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, and the other end of the resistor R6 is respectively connected to the clamping circuit and the relay driving module.

[0017] One of the preferred solutions is that the clamping circuit includes a clamping diode D1; the anode of the clamping diode D1 is respectively connected to the first current limiting circuit and the relay driving module, and the cathode of the clamping diode D1 is respectively connected to the DIP switch SW1 and the timing driving module.

[0018] One of the preferred solutions, the timing drive module includes a timing drive circuit, a double diode VD1, a second current limiting circuit, and a second voltage stabilizing circuit; the 1-pin of the double diode VD1 is connected to the RELAY_CLOSE_IO pin of the single-chip microcomputer, the 2-pin of the double diode VD1 is connected to the timing drive circuit, the timing drive circuit is respectively connected to the forced closing and locking circuit and the power supply terminal, the 3-pin of the double diode VD1 is connected to the second current limiting circuit, and the other end of the second current limiting circuit is respectively connected to the second voltage stabilizing circuit and the relay drive module.

[0019] One of the preferred solutions, the timing drive circuit includes a resistor R1, a capacitor C1, a resistor R3, a resistor R2, and a switching tube Q1;

[0020] The gate of the switching tube Q1 is respectively connected to the resistor R2 and the resistor R3, the other end of the resistor R3 is connected to the capacitor C1, and the other end of the capacitor C1 is respectively connected to the resistor R1 and the forced closing and locking circuit; the source of the switching tube Q1 is respectively connected to the other ends of the resistor R2 and the resistor R1 and the power supply terminal; the drain of the switching tube Q1 is connected to the 2-pin of the double diode VD1.

[0021] One of the preferred solutions, the timing drive time of the timing drive circuit is:

[0022] U c = U*(1 - e t / RC )

[0023] Wherein, U c is the voltage at point c, U is the initial voltage, R is the sum of the resistance values of resistor R2 and resistor R3, C is the capacitance value of capacitor C1, and e is the exponential parameter.

[0024] One of the preferred solutions, the second current limiting circuit includes a resistor R5; one end of the resistor R5 is connected to the 3-pin of the double diode VD1, and the other end of the resistor R5 is respectively connected to the relay drive module and the second voltage stabilizing circuit.

[0025] One of the preferred solutions, the second voltage stabilizing circuit includes a resistor R4; one end of the resistor R4 is respectively connected to the relay drive module and the second current limiting circuit, and the other end of the resistor R4 is grounded.

[0026] In the above technical solution of the present utility model, the control circuit of the built-in load switch includes: a relay driving module, a forced closing and locking circuit, a timing driving module, and a first voltage stabilizing circuit; the relay driving module is respectively connected to the forced closing and locking circuit, the timing driving module, and the first voltage stabilizing circuit, and the forced closing and locking circuit is connected to the timing driving module; the forced closing and locking circuit is used to drive the relay driving module to control the load switch to perform a forced closing operation in an abnormal state; the timing driving module is used to generate a timing driving signal matching the relay and act on the relay driving module to control the opening or closing operation of the load switch at a fixed time. The present utility model solves the technical problems of collective tripping at the user end caused by abnormal states and how to drive the relay at a fixed time to control the closing and opening of the user end.

[0027] In the present utility model, the DIP switch SW1 is used as the trigger signal of the load switch, the clamping diode D1 of the forced closing and locking circuit is used to achieve the function of shielding tripping, and the forced closing is realized through the timing driving module, so that in abnormal situations, such as hacker attacks or MCU abnormal situations, collective tripping events will not occur at the user end.

[0028] In the present utility model, since the load switch is a magnetic latching relay and cannot be powered for a long time, otherwise the coil will be burned out. According to the driving time required by the load switch, the timing driving module is used to drive the load switch to automatically close at a fixed time, and different load switches can be adapted by adjusting the components of the timing driving circuit, with low cost and convenient use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model, and those of ordinary skill in the art can also obtain other drawings based on the structures shown in these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of a control circuit of a built-in load switch according to an embodiment of the present utility model;

[0031] Figure 2 It is a circuit diagram of a control circuit of a built-in load switch according to an embodiment of the present utility model.

[0032] The realization of the purpose, functional characteristics, and advantages of the present utility model will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Next, in combination with the accompanying drawings in the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present utility model.

[0034] It should be noted that all directional indications (such as up, down,...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0035] In addition, in the present utility model, descriptions such as "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0036] Moreover, the technical solutions between the various embodiments of the present utility model can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0037] See Figure 1 - Figure 2 , according to one aspect of the present utility model, the present utility model provides a control circuit for an internal load switch, wherein the control circuit for the internal load switch includes:

[0038] A relay drive module, a forced closing and locking circuit, a timing drive module, and a first voltage stabilization circuit;

[0039] The relay drive module is respectively connected to the forced closing and locking circuit, the timing drive module, and the first voltage stabilization circuit, and the forced closing and locking circuit is connected to the timing drive module;

[0040] The forced closing and locking circuit is used to drive the relay drive module to control the load switch to perform a forced closing operation in an abnormal state; the timing drive module is used to generate a timing drive signal matching the relay and act on the relay drive module to control the opening or closing operation of the load switch at a fixed time.

[0041] Specifically, in this embodiment, the relay drive module includes a relay drive chip U1;

[0042] The 1st pin of the relay driver chip U1 is connected to the timing drive module;

[0043] The 2nd pin of the relay driver chip U1 is grounded;

[0044] The 3rd pin of the relay driver chip U1 is respectively connected to the forced closing locking circuit and the first voltage stabilizing circuit;

[0045] The 4th and 5th pins of the relay driver chip U1 are connected to the load switch through an induction coil; after receiving the drive signal output by the relay driver chip U1, the induction coil obtains a positive / negative voltage, so as to act on the load switch for tripping or closing operations; the other end of the load switch is respectively connected to the power grid and the user side;

[0046] The 6th pin of the relay driver chip U1 is connected to the power supply terminal.

[0047] Specifically, in this embodiment, the forced closing locking circuit includes a first current limiting circuit, a clamping circuit and a DIP switch SW1; one end of the first current limiting circuit is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, and through the RELAY_OPEN_IO pin of the single-chip microcomputer, that is, the I / O port of the single-chip microcomputer issues a tripping signal. The other end of the first current limiting circuit is respectively connected to the clamping circuit and the relay drive module. The other end of the clamping circuit is respectively connected to the timing drive module and the DIP switch SW1. The other end of the DIP switch SW1 is grounded; when the DIP switch SW1 is closed, the clamping diode D1 clamps the RELAY_OPEN_IO tripping signal output by the single-chip microcomputer after the DIP switch SW1 is closed, making the tripping signal invalid; the forced closing locking circuit uses the DIP switch SW1 as the trigger signal of the load switch, shields the tripping through the clamping diode D1, and cooperates with the timing drive module to realize the forced closing of the load switch, avoiding the occurrence of collective tripping events at the user side when being hacked or when the MCU is abnormal, and has higher reliability.

[0048] Specifically, in this embodiment, the first current limiting circuit includes a resistor R6; one end of the resistor R6 is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, and the other end of the resistor R6 is respectively connected to the anode of the clamping diode D1 of the clamping circuit and the 3rd pin of the relay driver chip U1; the first current limiting circuit limits the current magnitude in the circuit to protect other components in the circuit from being damaged by excessive current and prevent the single-chip microcomputer from short-circuiting to the ground.

[0049] Specifically, in this embodiment, the clamping circuit includes a clamping diode D1; the anode of the clamping diode D1 is respectively connected to the first current limiting circuit and the relay driving module, and the cathode of the clamping diode D1 is respectively connected to the DIP switch SW1 and the 3rd pin of the relay driving chip U1; the clamping circuit is used to prevent the single-chip microcomputer signal from interfering with the timing driving signal.

[0050] Specifically, in this embodiment, the control circuit of the built-in load switch further includes a first voltage stabilizing circuit, one end of the first voltage stabilizing circuit is connected to the relay driving module, and the other end of the first voltage stabilizing circuit is grounded; the first voltage stabilizing circuit includes a resistor R7, one end of the resistor R7 is connected to the 3rd pin of the relay driving chip U1, and the other end of the resistor R7 is grounded; through the first voltage stabilizing circuit, when the input voltage changes, the voltage drop of the first voltage stabilizing circuit will change accordingly, so as to maintain the stability of the output voltage and the stable level.

[0051] Specifically, in this embodiment, the timing driving module includes a timing driving circuit, a double diode VD1, a second current limiting circuit, and a second voltage stabilizing circuit; the 1st pin of the double diode VD1 is connected to the RELAY_CLOSE_IO pin of the single-chip microcomputer. Through the RELAY_CLOSE_IO pin of the single-chip microcomputer, that is, the I / O port of the single-chip microcomputer issues a closing signal. The 2nd pin of the double diode VD1 is connected to the timing driving circuit, the timing driving circuit is respectively connected to the forced closing locking circuit and the power supply terminal, the 3rd pin of the double diode VD1 is connected to the second current limiting circuit, and the other end of the second current limiting circuit is respectively connected to the second voltage stabilizing circuit and the relay driving module.

[0052] Specifically, in this embodiment, the timing drive circuit includes a resistor R1, a capacitor C1, a resistor R3, a resistor R2, and a switching transistor Q1; the gate of the switching transistor Q1 is respectively connected to the resistor R2 and the resistor R3, the other end of the resistor R3 is connected to the capacitor C1, and the other end of the capacitor C1 is respectively connected to the resistor R1, the 1-pin of the DIP switch SW1, and the cathode of the clamping diode D1; the source of the switching transistor Q1 is respectively connected to the resistor R2, the other end of the resistor R1, and the power supply terminal; the drain of the switching transistor Q1 is connected to the 2-pin of the double diode VD1; the resistor R1 is a pull-up resistor, and the switching transistor Q1 uses a P-channel MOSFET switching transistor. When the DIP switch SW1 is closed, a high level is generated simultaneously to drive the relay drive chip U1 to control the load switch to close. Since the load switch is a magnetic latching relay and cannot be powered for a long time, otherwise the coil will burn out. Therefore, the timing drive circuit generates a timing drive signal according to the drive time required by the load switch, and sends the timing drive signal to the relay drive module, and drives the load switch to close or open automatically at a fixed time through the relay drive module, so as to ensure that the relay coil will not be continuously powered on and thus heat up and burn out.

[0053] Specifically, in this embodiment, the timing drive time of the timing drive circuit is:

[0054] U c = U*(1 - e t / RC )

[0055] Wherein, U c is the voltage at point b, U is the initial voltage, R is the sum of the resistance values of the resistor R2 and the resistor R3, C is the capacitance value of the capacitor C1, and e is the exponential parameter;

[0056] At the moment when the DIP switch SW1 is closed, point a is instantaneously grounded at this time, and V a = 0V. Due to the characteristic that the voltage difference across the capacitor C1 cannot change suddenly, the voltage V b at point b is also equal to 0V, that is, V a = V b = V c = 0V; at this time, V GS = V c - V d, the switching transistor Q1 conducts, and the 1-pin of the relay driver chip U1 obtains the voltage VCC*R4 / (R4+R5). The relay driver chip U1 issues a closing signal. The 5-pin of the relay driver chip U1 outputs RELAY_VCC, and the 4-pin of the relay driver chip U1 outputs 0V, enabling the induction coil to be powered on. The load switch completes the closing operation, enabling the grid to conduct with the user side; after the DIP switch SW1 is closed, the power supply terminal VCC will charge the capacitor C1 through the resistor R2 and the resistor R3. During the charging process, the voltages at point c and point b will slowly rise from 0V. Therefore, the V GS voltage of the switching transistor Q1 will change by 0V. During this process, when V GS >V GS(th) After that, where V GS is the voltage between the gate and source of the switching transistor, and V GS(th) is the threshold turn-on voltage of the switching transistor Q1, the switching transistor Q1 turns off. After the switch Q1 turns off, the 1-pin of the relay driver chip U1 is pulled down to 0V due to the pull-down effect of the resistor R4, and the relay driver chip U1 stops outputting. The 4-pin and 5-pin of the relay driver chip U1 output 0V, and the induction coil loses power, thus avoiding the problem of burnout due to the load switch being a magnetic latching relay and the induction coil being powered on for a long time. Among them, the off time of the switching transistor Q1 is the timing drive time, V c =V d +V GS(th) , V b =V c -(V dc *R3*R2), U c =V b , U = VCC.

[0057] Specifically, in this embodiment, the second current-limiting circuit includes a resistor R5; one end of the resistor R5 is connected to the 3-pin of the double diode VD1, and the other end of the resistor R5 is respectively connected to the 1-pin of the relay driver chip U1 and the second voltage-regulating circuit; the second current circuit limits the current magnitude in the circuit to protect other components in the circuit from excessive current damage and prevent the single-chip microcomputer from short-circuiting to the ground.

[0058] Specifically, in this embodiment, the second voltage-regulating circuit includes a resistor R4; one end of the resistor R4 is respectively connected to the 1-pin of the relay driver chip U1 and the second current-limiting circuit, and the other end of the resistor R4 is grounded; through the second voltage-regulating circuit, when the input voltage changes, the voltage drop of the second voltage-regulating circuit will change accordingly, so as to maintain the stability of the output voltage and stabilize the level.

[0059] Specifically, in this embodiment, under normal conditions, the relay driving module drives the relay chip to control the load switch to trip and close by sending a trip signal and a closing signal from the single-chip microcomputer; if there is an arrears situation at the user end, the relay driving module can drive the induction coil to disconnect the power supply of the user end through the load switch, and then send a reverse voltage after re-payment to close the load switch, thereby supplying power to the user end; therefore, the control circuit with the built-in load switch can immediately control the on / off of the power grid and the user end.

[0060] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied to other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A control circuit with a built-in load switch, characterized in that, Comprising: A relay driving module, a forced closing locking circuit, a timing driving module, and a first voltage stabilizing circuit; The relay driving module is respectively connected to the forced closing locking circuit, the timing driving module, and the first voltage stabilizing circuit, and the forced closing locking circuit is connected to the timing driving module; The forced closing locking circuit is used to drive the relay driving module to control the load switch to perform a forced closing operation in an abnormal state; the timing driving module is used to generate a timing driving signal matching the relay and act on the relay driving module to control the opening or closing operation of the load switch at a fixed time.

2. The control circuit of an internal load switch according to claim 1, wherein The relay driving module includes a relay driving chip U1; The pin 1 of the relay driving chip U1 is connected to the timing driving module; The pin 2 of the relay driving chip U1 is grounded; The pin 3 of the relay driving chip U1 is connected to the forced closing locking circuit; The pins 4 and 5 of the relay driving chip U1 are connected to the load switch through an induction coil; The pin 6 of the relay driving chip U1 is connected to the power supply terminal.

3. A control circuit for an internal load switch according to any one of claims 1-2, characterized in that, The forced closing locking circuit includes a first current limiting circuit, a clamping circuit, and a DIP switch SW1; One end of the first current limiting circuit is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, the other end of the first current limiting circuit is respectively connected to the clamping circuit and the relay driving module, the other end of the clamping circuit is respectively connected to the timing driving module and the DIP switch SW1, and the other end of the DIP switch SW1 is grounded.

4. The control circuit of an internal load switch according to claim 3, characterized in that, The first current limiting circuit includes a resistor R6; one end of the resistor R6 is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, and the other end of the resistor R6 is respectively connected to the clamping circuit and the relay driving module.

5. The control circuit of an internal load switch according to claim 3, characterized in that, The clamping circuit includes a clamping diode D1; the anode of the clamping diode D1 is respectively connected to the first current limiting circuit and the relay driving module, and the cathode of the clamping diode D1 is respectively connected to the DIP switch SW1 and the timing driving module.

6. A control circuit for an internal load switch according to any one of claims 1-2, characterized in that, The timing driving module includes a timing driving circuit, a double diode VD1, a second current limiting circuit, and a second voltage stabilizing circuit; the pin 1 of the double diode VD1 is connected to the RELAY_CLOSE_IO pin of the single-chip microcomputer, the pin 2 of the double diode VD1 is connected to the timing driving circuit, the timing driving circuit is respectively connected to the forced closing locking circuit and the power supply terminal, the pin 3 of the double diode VD1 is connected to the second current limiting circuit, and the other end of the second current limiting circuit is respectively connected to the second voltage stabilizing circuit and the relay driving module.

7. The control circuit of an internal load switch according to claim 6, characterized in that, The timing driving circuit includes a resistor R1, a capacitor C1, a resistor R3, a resistor R2, and a switching tube Q1; The gate of the switching tube Q1 is respectively connected to the resistor R2 and the resistor R3, the other end of the resistor R3 is connected to the capacitor C1, the other end of the capacitor C1 is respectively connected to the resistor R1 and the forced closing locking circuit; the source of the switching tube Q1 is respectively connected to the resistor R2, the other end of the resistor R1, and the power supply terminal; the drain of the switching tube Q1 is connected to the pin 2 of the double diode VD1.

8. A control circuit for an internal load switch according to claim 7, characterized in that, The timing driving time of the timing driving circuit is: U c = U * (1 - e t / RC ) Among them, U c is the voltage at point c, U is the initial voltage, R is the sum of the resistance values of resistor R2 and resistor R3, C is the capacitance value of capacitor C1, and e is the exponential parameter.

9. The control circuit of an internal load switch according to claim 6, characterized in that, The second current limiting circuit includes a resistor R5; one end of the resistor R5 is connected to the 3-pin of the double diode VD1, and the other end of the resistor R5 is respectively connected to the relay driving module and the second voltage stabilizing circuit.

10. A control circuit for an internal load switch according to claim 6, characterized in that, The second voltage stabilizing circuit includes a resistor R4; one end of the resistor R4 is respectively connected to the relay driving module and the second current limiting circuit, and the other end of the resistor R4 is grounded.

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