Control circuit with built-in load switch

Abstract

The invention discloses a control circuit with a built-in load switch. The control circuit comprises a relay driving module, a forced closing locking circuit and a timing driving module, the relay driving module is respectively connected with the forced closing locking circuit and the timing driving module, 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 invention, the technical problems of collective tripping of the user sides and how to drive the relay at regular time to control closing and opening of the user sides in an abnormal state are solved.

Description

Technical Field

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

[0002] At present, the existing load switch driving circuits are all based on single-chip microcomputer control and long-term continuous power supply, and the driving coil completes the closing and tripping actions. For example, the patent document with application number CN20228373.X discloses a magnetic latching relay driving circuit, including: the micro control unit in the control module outputs a corresponding voltage signal according to the received configuration instruction, the comparison module receives the voltage signal through the universal input / output interface of the control module, and outputs a corresponding control signal according to the comparison result between the voltage signal and the voltage reference signal, and the driving module outputs a corresponding driving signal to the magnetic latching relay according to the control signal, that is, the corresponding driving signal is generated by different voltage signals to control the magnetic latching relay to enter different working states, and the magnetic latching relay only needs to occupy a universal input / output interface (GPIO) of the micro control unit (MCU) to achieve the switching of different working states; this method can control the control module to control more magnetic latching relays in the application occasions 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 operating normally. When the MCU is abnormal or attacked by external hackers, it will cause an abnormality, and the instrument will collectively trip, and the client will be out of power and cannot be restored. Therefore, it is urgent to propose a control circuit with a built-in load switch to solve the technical problems of collective tripping of the user end under abnormal conditions and how to time the driving of the relay to control the closing and opening of the user end. Summary of the invention

[0003] The main purpose of the present invention is to propose a control circuit for a built-in load switch, aiming to solve the technical problems of collective tripping of user ends under abnormal conditions and how to time the driving of relays to control the closing and opening of the user ends.

[0004] To achieve the above object, the present invention provides a control circuit of a built-in load switch, wherein the control circuit of the built-in load switch comprises:

[0005] Relay drive module, forced closing lock circuit and timing drive module;

[0006] The relay drive module is connected to the forced closing lock circuit and the timing drive module respectively, and the forced closing lock 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 forced closing operation under abnormal conditions;

[0008] The timing drive module is used to generate a timing drive signal matching the relay, and acts on the relay drive module to control the opening or closing operation of the load switch in a timing manner.

[0009] In one of the preferred solutions, the relay driving module includes a relay driving chip U1;

[0010] Pin 1 of the relay driver chip U1 is connected to the timing driver module;

[0011] Pin 2 of the relay driver chip U1 is grounded;

[0012] Pin 3 of the relay driver chip U1 is connected to the forced closing locking circuit;

[0013] Pins 4 and 5 of the relay driver chip U1 are connected to the load switch via an induction coil;

[0014] Pin 6 of the relay driver chip U1 is connected to the power supply terminal.

[0015] In one preferred embodiment, the forced closing locking circuit includes a first current limiting circuit, a clamping circuit and a DIP switch SW1;

[0016] One end of the first current limiting circuit is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, and the other end of the first current limiting circuit is respectively connected to the clamping circuit and the relay driving module, and 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.

[0017] In one of the preferred solutions, 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.

[0018] In one of the preferred solutions, 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.

[0019] One of the preferred schemes, the timing drive module includes a timing drive circuit, a dual diode VD1, a second current limiting circuit, and a second voltage stabilizing circuit; pin 1 of the dual diode VD1 is connected to the RELAY_CLOSE_IO pin of the single-chip microcomputer, pin 2 of the dual diode VD1 is connected to the timing drive circuit, the timing drive circuit is respectively connected to the forced closing locking circuit and the power supply end, pin 3 of the dual 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.

[0020] In one preferred solution, the timing drive circuit includes a resistor R1, a capacitor C1, a resistor R3, a resistor R2 and a switch tube Q1;

[0021] The gate of the switch tube Q1 is connected to the resistor R2 and the resistor R3 respectively, the other end of the resistor R3 is connected to the capacitor C1, and the other end of the capacitor C1 is connected to the resistor R1 and the forced closing locking circuit respectively; the source of the switch tube Q1 is connected to the other end of the resistor R2 and the resistor R1 and the power supply end respectively; the drain of the switch tube Q1 is connected to the 2nd pin of the dual diode VD1.

[0022] In one of the preferred solutions, the timing driving time of the timing driving circuit is:

[0023] U c =U*(1-e t / RC )

[0024] Among them, U c is the voltage at point c, U is the initial voltage, R is the resistance value of resistor R2 and resistor R3, C is the capacitance value of capacitor C1, and e is an index parameter.

[0025] In one of the preferred solutions, the second current limiting circuit includes a resistor R5; one end of the resistor R5 is connected to pin 3 of the dual diode VD1, and the other end of the resistor R5 is respectively connected to the relay drive module and the second voltage stabilizing circuit.

[0026] In 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 driving module and the second current limiting circuit, and the other end of the resistor R4 is grounded.

[0027] In the above technical solution of the present invention, the control circuit of the built-in load switch includes: a relay drive module, a forced closing lock circuit and a timing drive module; the relay drive module is respectively connected to the forced closing lock circuit and the timing drive module, and the forced closing lock circuit is connected to the timing drive module; the forced closing lock circuit is used to drive the relay drive module to control the load switch to perform a forced closing operation under 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. The present invention solves the technical problems of collective tripping of the user end under abnormal conditions and how to time the drive relay to control the closing and opening of the user end.

[0028] In the present invention, the dip switch SW1 is used as the trigger signal of the load switch, the clamping diode D1 of the forced closing locking circuit is used to realize the function of shielding tripping, and the forced closing is realized by the timing drive module, so that in abnormal situations, such as hacker attacks or MCU abnormal situations, collective tripping events will not occur on the user side.

[0029] In the present invention, since the load switch is a magnetic latching relay, it cannot be powered for a long time, otherwise the coil will be burned. According to the driving time required by the load switch, the load switch is driven by the timing drive module to automatically close, and different load switches can be adapted by adjusting the components of the timing drive circuit, which has low cost and is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0031] Figure 1 This is a schematic diagram of the structure of a control circuit with a built-in load switch according to an embodiment of the present invention;

[0032] Figure 2 The present invention is a circuit diagram of a control circuit with a built-in load switch according to an embodiment of the present invention.

[0033] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0037] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] See also Figure 1-Figure 2 According to one aspect of the present invention, the present invention provides a control circuit of a built-in load switch, wherein the control circuit of the built-in load switch comprises:

[0039] Relay drive module, forced closing lock circuit and timing drive module;

[0040] The relay drive module is connected to the forced closing lock circuit and the timing drive module respectively, and the forced closing lock circuit is connected to the timing drive module;

[0041] The forced closing locking circuit is used to drive the relay driving module to control the load switch to perform forced closing operation under abnormal conditions;

[0042] The timing drive module is used to generate a timing drive signal matching the relay, and acts on the relay drive module to control the opening or closing operation of the load switch in a timing manner.

[0043] Specifically, in this embodiment, the relay driving module includes a relay driving chip U1;

[0044] Pin 1 of the relay driver chip U1 is connected to the timing driver module;

[0045] Pin 2 of the relay driver chip U1 is grounded;

[0046] The 3 pins of the relay driving chip U1 are respectively connected to the forced closing locking circuit and the first voltage stabilizing circuit;

[0047] Pins 4 and 5 of the relay driver chip U1 are connected to the load switch through an induction coil; after the induction coil receives the drive signal output by the relay driver chip U1, a positive / negative voltage is obtained, thereby acting on the load switch to perform a tripping or closing operation; the other end of the load switch is respectively connected to the power grid and the user end;

[0048] Pin 6 of the relay driver chip U1 is connected to the power supply terminal.

[0049] Specifically, in the present embodiment, the forced closing locking circuit includes a first current limiting circuit, a clamping circuit and a dial switch SW1; one end of the first current limiting circuit is connected to the RELAY_OPEN_IO pin of the single-chip microcomputer, and a tripping signal is sent through the RELAY_OPEN_IO pin of the single-chip microcomputer, that is, the I / O port 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 dial switch SW1, and the other end of the dial switch SW1 is grounded; when the dial switch SW1 is closed, the clamping diode D1 clamps the RELAY_OPEN_IO tripping signal output by the single-chip microcomputer after the dial switch SW1 is closed, so that the tripping signal is invalid; the forced closing locking circuit uses the dial switch SW1 as the trigger signal of the load switch, realizes shielding tripping through the clamping diode D1, and cooperates with the timing driving module to realize forced closing of the load switch, so as to avoid collective tripping events at the user end when hacker attacks or MCU abnormalities occur, and has higher reliability.

[0050] Specifically, in the present embodiment, the first current limiting circuit comprises 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 3 pin of the relay driving chip U1; the current in the circuit is limited by the first current limiting circuit to protect other components in the circuit from being damaged by excessive current and to prevent the single-chip microcomputer from being short-circuited to the ground.

[0051] 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 3-pin of the relay driving chip U1; the clamping circuit is used to prevent the microcontroller signal and the timing driving signal from interfering with each other.

[0052] Specifically, in this embodiment, the control circuit of the built-in load switch also 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 pin 3 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, thereby maintaining the stability of the output voltage and the stable level.

[0053] Specifically, in this embodiment, the timing drive module includes a timing drive circuit, a dual diode VD1, a second current limiting circuit, and a second voltage stabilizing circuit; pin 1 of the dual diode VD1 is connected to the RELAY_CLOSE_IO pin of the single-chip microcomputer, and a closing signal is sent through the RELAY_CLOSE_IO pin of the single-chip microcomputer, that is, the I / O port of the single-chip microcomputer. Pin 2 of the dual diode VD1 is connected to the timing drive circuit, and the timing drive circuit is respectively connected to the forced closing locking circuit and the power supply end, and pin 3 of the dual 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.

[0054] Specifically, in this embodiment, the timing drive circuit includes a resistor R1, a capacitor C1, a resistor R3, a resistor R2 and a switch tube Q1; the gate of the switch tube Q1 is connected to the resistor R2 and the resistor R3 respectively, the other end of the resistor R3 is connected to the capacitor C1, the other end of the capacitor C1 is connected to the resistor R1, the 1 pin of the dip switch SW1 and the cathode of the clamping diode D1 respectively; the source of the switch tube Q1 is connected to the other end of the resistor R2 and the resistor R1 and the power supply end respectively; the drain of the switch tube Q1 is connected to the 2 pin of the dual diode VD1; the resistor R1 is a pull-up The switch tube Q1 adopts a P-channel MOSFET switch tube. When the dip switch SW1 is closed, a high level is generated at the same time, driving the relay driver chip U1 to control the load switch to close. Because the load switch is a magnetic latching relay, it 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 driving time required by the load switch, and sends the timing drive signal to the relay drive module. The relay drive module drives the load switch to be automatically closed or opened at a certain time, thereby ensuring that the relay coil will not be continuously powered, thereby heating and burning out.

[0055] Specifically, in this embodiment, the timing driving time of the timing driving circuit is:

[0056] U c =U*(1-e t / RC )

[0057] Among them, U c is the voltage at point b, U is the initial voltage, R is the resistance value of resistor R2 and resistor R3, C is the capacitance value of capacitor C1, and e is an index parameter;

[0058] At the moment when the DIP switch SW1 is closed, point a is instantly grounded, V a =0V. Due to the characteristic that the voltage difference across capacitor C1 cannot change suddenly, the voltage V at point b b It is also equal to 0V, that is, V a =Vb =V c =0V; at this time, V GS =V c -V d , the switch tube Q1 is turned on, the 1 pin of the relay driver chip U1 receives the voltage VCC*R4 / (R4+R5), the relay driver chip U1 sends 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, so that the induction coil is energized, the load switch completes the closing operation, and the power grid is connected to the user end; after the dip switch SW1 is closed, the power supply end VCC will charge the capacitor C1 through the resistor R2 and the resistor R3. During the charging process, the voltage at point c and point b will slowly rise from 0V, so the V of the switch tube Q1 GS The voltage will change to 0V. During this process, when V GS >V GS(th) After that, V GS is the voltage between the gate and source of the switch tube, V GS(th) is the threshold turn-on voltage of the switch tube Q1. The switch tube Q1 is turned off. After the switch Q1 is turned 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. The relay driver chip U1 stops outputting. The 4 and 5 pins of the relay driver chip U1 output 0V, and the induction coil loses power, thereby avoiding the problem of the induction coil being burned out due to the long-term use of the load switch being a magnetic latching relay. Among them, the time when the switch tube Q1 is turned off 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.

[0059] Specifically, in the present embodiment, the second current limiting circuit comprises a resistor R5; one end of the resistor R5 is connected to pin 3 of the dual diode VD1, and the other end of the resistor R5 is respectively connected to pin 1 of the relay driver chip U1 and the second voltage stabilizing circuit; the current in the circuit is limited by the second current circuit to protect other components in the circuit from being damaged by excessive current and to prevent the single-chip microcomputer from being short-circuited to the ground.

[0060] Specifically, in this embodiment, the second voltage stabilizing circuit includes a resistor R4; one end of the resistor R4 is respectively connected to pin 1 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 stabilizing circuit, when the input voltage changes, the voltage drop of the second voltage stabilizing circuit will change accordingly, thereby maintaining a stable output voltage and a stable level.

[0061] Specifically, in the present embodiment, under normal conditions, the relay driving module sends a tripping signal and a closing signal by the single-chip microcomputer to drive the relay chip to control the load switch to perform tripping and closing operations; if the user end is in arrears, 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 payment to close the load switch, thereby supplying power to the user end; therefore, the control circuit of the built-in load switch can instantly control the on and off of the power grid and the user end.

[0062] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A control circuit with a built-in load switch, characterized in that: include: Relay drive module, forced closing lock circuit and timing drive module; The relay drive module is connected to the forced closing lock circuit and the timing drive module respectively, and the forced closing lock circuit is connected to the timing drive module; The forced closing locking circuit is used to drive the relay driving module to control the load switch to perform forced closing operation under abnormal conditions; The timing drive module is used to generate a timing drive signal matching the relay, and acts on the relay drive module to control the opening or closing operation of the load switch in a timing manner.

2. A control circuit with a built-in load switch according to claim 1, characterized in that: The relay driving module includes a relay driving chip U1; Pin 1 of the relay driver chip U1 is connected to the timing driver module; Pin 2 of the relay driver chip U1 is grounded; Pin 3 of the relay driver chip U1 is connected to the forced closing locking circuit; Pins 4 and 5 of the relay driver chip U1 are connected to the load switch via an induction coil; Pin 6 of the relay driver chip U1 is connected to the power supply terminal.

3. A control circuit for a built-in load switch according to any one of claims 1 to 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, and the other end of the first current limiting circuit is respectively connected to the clamping circuit and the relay driving module, and 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. A control circuit with a built-in 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 connected to the clamping circuit and the relay driving module respectively.

5. The control circuit of a built-in 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 a built-in load switch according to any one of claims 1 to 2, characterized in that: The timing drive module includes a timing drive circuit, a dual diode VD1, a second current limiting circuit, and a second voltage stabilizing circuit; pin 1 of the dual diode VD1 is connected to the RELAY_CLOSE_IO pin of the single-chip microcomputer, pin 2 of the dual diode VD1 is connected to the timing drive circuit, the timing drive circuit is respectively connected to the forced closing locking circuit and the power supply end, pin 3 of the dual 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.

7. A control circuit with a built-in load switch according to claim 6, characterized in that: The timing drive circuit includes a resistor R1, a capacitor C1, a resistor R3, a resistor R2 and a switch tube Q1; The gate of the switch tube Q1 is connected to the resistor R2 and the resistor R3 respectively, the other end of the resistor R3 is connected to the capacitor C1, and the other end of the capacitor C1 is connected to the resistor R1 and the forced closing locking circuit respectively; the source of the switch tube Q1 is connected to the other end of the resistor R2 and the resistor R1 and the power supply end respectively; the drain of the switch tube Q1 is connected to the 2nd pin of the dual diode VD1.

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

9. A control circuit with a built-in 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 dual diode VD1, and the other end of the resistor R5 is connected to the relay drive module and the second voltage stabilizing circuit respectively.

10. A control circuit with a built-in 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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