Coil current switching control circuit

Abstract

The utility model relates to a coil current switching control circuit, and belongs to the technical field of control circuits. The coil current switching control circuit comprises a signal output circuit; the first end of the operational amplifier circuit is connected with the first end of the signal output circuit; the first end of the switching circuit is connected with the second end of the operational amplifier circuit, the switching circuit is further used for being connected with a target coil in parallel, and the connection point of the second end of the switching circuit and the third end of the operational amplifier circuit is connected with the grounding end of the coil current switching control circuit.

Description

Technical Field

[0001] This utility model relates to the technical field of control circuits, and more specifically, to a coil circuit switching control circuit. Background Technology

[0002] With the widespread application of electrical protection devices such as trip units and circuit breakers, the coil current of these devices varies in different operating modes, namely high-current mode and low-current mode. To achieve switching between these modes, a microcontroller typically outputs a PWM control signal, adjusting the duty cycle to switch between modes. However, microcontrollers generally operate at low voltages, requiring a power supply chip to convert the input high voltage to power the microcontroller circuit. This limits the microcontroller's drive current capability, making it difficult to meet the coil's driving requirements. Utility Model Content

[0003] Embodiments of this disclosure provide a coil current switching control circuit.

[0004] According to a first aspect of the present invention, a coil current switching control circuit is provided, the coil current switching control circuit comprising:

[0005] Signal output circuit;

[0006] An operational amplifier circuit, wherein the first terminal of the operational amplifier circuit is connected to the first terminal of the signal output circuit;

[0007] A switching circuit, wherein the first terminal of the switching circuit is connected to the second terminal of the operational amplifier circuit, the switching circuit is also used to be connected in parallel with the target coil, and the connection point of the second terminal of the switching circuit and the third terminal of the operational amplifier circuit is connected to the ground terminal of the coil current switching control circuit.

[0008] The signal output circuit responds to the high-current start signal and outputs a first electrical signal; the operational amplifier circuit responds to the first electrical signal and outputs a second electrical signal; the switching circuit responds to the second electrical signal and turns on, causing the terminal voltage of the third terminal of the operational amplifier circuit to rise; when the terminal voltage of the third terminal of the operational amplifier circuit rises to a set voltage, a third electrical signal is output; and the switching circuit responds to the third electrical signal and turns off.

[0009] Optionally, the signal output circuit includes an output control chip and a voltage divider control circuit;

[0010] The first terminal of the output control chip is connected to the first terminal of the voltage divider control circuit, and the second terminal of the voltage divider control circuit is connected to the first terminal of the operational amplifier circuit.

[0011] Optionally, the voltage divider control circuit includes a nineteenth resistor, a twenty-third resistor, a twenty-sixth resistor, and a sixth switching transistor;

[0012] Wherein, the first end of the nineteenth resistor is connected to the power supply terminal of the coil current switching control circuit, the second end of the nineteenth resistor is connected to the first end of the twenty-third resistor, the second end of the twenty-third resistor is connected to the first end of the twenty-sixth resistor, the second end of the twenty-sixth resistor is connected to the ground terminal of the coil current switching control circuit, the gate of the sixth switching transistor is connected to the first terminal of the output control chip, the source of the sixth switching transistor is connected to the second end of the twenty-third resistor, and the drain of the sixth switching transistor is connected to the first end of the twenty-third resistor.

[0013] Optionally, the voltage divider control circuit further includes a fifteenth capacitor, the first end of which is connected to the source of the sixth switching transistor, and the second end of which is connected to the ground terminal of the coil current switching control circuit.

[0014] Optionally, the operational amplifier circuit includes an operational amplifier, the non-inverting input terminal of the operational amplifier is connected to the first terminal of the signal output circuit, the inverting input terminal of the operational amplifier is connected to the ground terminal of the coil current switching control circuit, and the output terminal of the operational amplifier is connected to the first terminal of the switching circuit.

[0015] Optionally, the operational amplifier circuit further includes an eleventh capacitor and an eighteenth resistor. The eleventh capacitor is connected across the ground terminal of the coil current switching control circuit and the inverting input terminal of the operational amplifier, and the eighteenth resistor is connected in series between the ground terminal of the coil current switching control circuit and the inverting input terminal of the operational amplifier.

[0016] Optionally, the switching circuit includes a switch control chip and a control switch circuit;

[0017] The first terminal of the switch control chip is connected to the second terminal of the operational amplifier circuit, the second terminal of the switch control chip is connected to the first terminal of the control switch circuit, and the connection point between the second terminal of the control switch circuit and the third terminal of the operational amplifier circuit is connected to the ground terminal of the coil current switching control circuit.

[0018] Optionally, the control switch circuit includes a sixth diode, a twelfth diode, an eighth resistor, a ninth resistor, and a third switching transistor. The cathode of the sixth diode is connected to the first end of the target coil, the anode of the sixth diode is connected to the second end of the target coil, the drain of the third switching transistor is connected to the anode of the sixth diode, the source of the third switching transistor is connected to the ground terminal of the coil current switching control circuit, the gate of the third switching transistor is connected to the first end of the eighth resistor, the second end of the eighth resistor is connected to the anode of the twelfth diode, the cathode of the twelfth diode is connected to the second end of the switch control chip, the first end of the ninth resistor is connected to the first end of the eighth resistor, and the second end of the ninth resistor is connected to the cathode of the twelfth diode.

[0019] One technical advantage of this invention is that the coil current switching control circuit can control the target coil to operate stably through the cooperation of the signal output circuit, operational amplifier circuit and switching circuit. Under the premise of achieving switching control between high current mode and low current mode, it meets the power supply requirements of the coil and improves the stability of the coil operation of the electrical protection device.

[0020] Other features and advantages of the present invention will become clear from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, illustrate embodiments of the present invention and, together with the specification, serve to explain the principles of the present invention.

[0022] Figure 1 This is a structural block diagram of a coil circuit switching control circuit according to one embodiment;

[0023] Figure 2 This is a circuit diagram of a coil circuit switching control circuit according to one embodiment. Detailed Implementation

[0024] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0025] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0026] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0027] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0029] See Figure 1 As shown, an integrated charging, discharging, and driving system 1000 according to an embodiment of this disclosure will be described.

[0030] The coil current switching control circuit of this disclosure includes:

[0031] Signal output circuit 10;

[0032] Operational amplifier circuit 20, the first terminal of operational amplifier circuit 20 is connected to the first terminal of signal output circuit 10;

[0033] The switching circuit 30 has its first terminal connected to the second terminal of the operational amplifier circuit 20. The switching circuit 30 is also used to be connected in parallel with the target coil 1. The connection point between the second terminal of the switching circuit 30 and the third terminal of the operational amplifier circuit 20 is connected to the ground terminal of the coil current switching control circuit.

[0034] Specifically, the signal output circuit 10 responds to the high-current start signal and outputs a first electrical signal; the operational amplifier circuit 20 responds to the first electrical signal and outputs a second electrical signal; the switching circuit 30 responds to the second electrical signal and turns on, causing the terminal voltage of the third terminal of the operational amplifier circuit 20 to rise; when the terminal voltage of the third terminal of the operational amplifier circuit 20 rises to a set voltage, a third electrical signal is output; and the switching circuit 30 responds to the third electrical signal and turns off.

[0035] In this embodiment, as Figure 1As shown, signal output circuit 10 responds to the high-current start signal and outputs a high-level first electrical signal. Operational amplifier circuit 20 responds to the high-level first electrical signal and outputs a high-level second electrical signal to switching circuit 30. The COMP terminal of switching circuit 30 is connected to the power supply terminal VDD of the coil current switching control circuit, and switching circuit 30 is turned on, causing the voltage of resistor R20 to gradually increase until the voltage at the third terminal of operational amplifier circuit 20 is greater than the voltage at the first terminal of operational amplifier circuit 20. The output of operational amplifier circuit 20 then reverses from VDD to GND. Subsequently, COMP terminal of switching circuit 30 is connected to the ground terminal GND of coil current switching control circuit, switching circuit 30 is turned off, the voltage of resistor R20 drops, and the voltage at the third terminal of operational amplifier circuit 20 is less than the voltage at the first terminal of operational amplifier circuit 20. The COMP terminal of switching circuit 30 is then connected to the power supply terminal VDD of coil current switching control circuit, and signal output circuit 10 starts working again. This cycle repeats to achieve switching control between high-current mode and low-current mode.

[0036] In this embodiment, the target coil 1 is connected to electrical energy through the input terminal S1.

[0037] In this embodiment, the coil current switching control circuit can control the target coil 1 to operate stably through the cooperation of the signal output circuit 10, the operational amplifier circuit 20 and the switching circuit 30. Under the premise of realizing the switching control between high current mode and low current mode, it meets the power supply requirements of the coil and improves the stability of the coil operation of the electrical protection device.

[0038] In some embodiments, the signal output circuit 10 includes an output control chip and a voltage divider control circuit;

[0039] The first terminal of the output control chip is connected to the first terminal of the voltage divider control circuit, and the second terminal of the voltage divider control circuit is connected to the first terminal of the operational amplifier circuit 20.

[0040] In some embodiments, the voltage divider control circuit includes a nineteenth resistor R19, a twenty-third resistor R23, a twenty-sixth resistor R26, and a sixth switch Q6;

[0041] Specifically, the first end of the nineteenth resistor R19 is connected to the power supply terminal of the coil current switching control circuit; the second end of the nineteenth resistor R19 is connected to the first end of the twenty-third resistor R23; the second end of the twenty-third resistor R23 is connected to the first end of the twenty-sixth resistor R26; the second end of the twenty-sixth resistor R26 is connected to the ground terminal of the coil current switching control circuit; the gate of the sixth switching transistor Q6 is connected to the first terminal of the output control chip; the source of the sixth switching transistor Q6 is connected to the second end of the twenty-third resistor R23; and the drain of the sixth switching transistor Q6 is connected to the first end of the twenty-third resistor R23.

[0042] In this embodiment, as Figure 2 As shown, when the first terminal of the signal output circuit 10 outputs a high level, the sixth switch Q6 is turned on, and the twenty-third resistor R23 is bypassed. The power supply terminal VDD of the coil current switching control circuit has a higher voltage drop across the twenty-sixth resistor R26. However, when the signal output circuit 10 outputs a low level, the sixth switch Q6 is turned off, and there is also a voltage drop across the twenty-third resistor R23, thus reducing the voltage drop across the twenty-sixth resistor R26.

[0043] In this embodiment, the sixth switch Q6 can be a MOSFET.

[0044] In this embodiment, as Figure 2 As shown, the first terminal of the signal output circuit 10 is its operating reference level. When the reference level increases, the voltage across the twentieth resistor R20 increases, resulting in a larger current in the target coil 1. Similarly, when the reference level decreases, the current in the target coil 1 also decreases. The voltage level at the first terminal of the signal output circuit 10 is the voltage drop across the twentieth resistor R26, which is the voltage division of the power supply terminal VDD of the coil current switching control circuit.

[0045] In some embodiments, the voltage divider control circuit further includes a fifteenth capacitor C15, the first end of which is connected to the source of the sixth switching transistor Q6, and the second end of which is connected to the ground terminal of the coil current switching control circuit.

[0046] In this embodiment, the fifteenth capacitor C15 is a filter capacitor, which can further improve the stability of the coil current switching control circuit.

[0047] In some embodiments, the operational amplifier circuit 20 includes an operational amplifier U2, the non-inverting input terminal of the operational amplifier U2 is connected to the first terminal of the signal output circuit 10, the inverting input terminal of the operational amplifier U2 is connected to the ground terminal of the coil current switching control circuit, and the output terminal of the operational amplifier U2 is connected to the first terminal of the switching circuit 30.

[0048] In some embodiments, the operational amplifier circuit 20 further includes an eleventh capacitor C11 and an eighteenth resistor R18. The eleventh capacitor C11 is connected across the ground terminal of the coil current switching control circuit and the inverting input terminal of the operational amplifier U2, and the eighteenth resistor R18 is connected in series between the ground terminal of the coil current switching control circuit and the inverting input terminal of the operational amplifier U2.

[0049] In this embodiment, by using the eleventh capacitor C11 and the eighteenth resistor R18 as RC filters, the stability of the coil current switching control circuit can be further improved.

[0050] In some embodiments, the switching circuit 30 includes a switch control chip U1 and a control switch circuit;

[0051] The first terminal of the switch control chip U1 is connected to the second terminal of the operational amplifier circuit 20, the second terminal of the switch control chip U1 is connected to the first terminal of the control switch circuit, and the connection point between the second terminal of the control switch circuit and the third terminal of the operational amplifier circuit 20 is connected to the ground terminal of the coil current switching control circuit.

[0052] In some embodiments, the control switch circuit includes a sixth diode D6, a twelfth diode D12, an eighth resistor R8, a ninth resistor R9, and a third switch Q3. The cathode of the sixth diode D6 is connected to the first end of the target coil 1, and the anode of the sixth diode D6 is connected to the second end of the target coil 1. The drain of the third switch Q3 is connected to the anode of the sixth diode D6, the source of the third switch Q3 is connected to the ground terminal of the coil current switching control circuit, the gate of the third switch Q3 is connected to the first end of the eighth resistor R8, the second end of the eighth resistor R8 is connected to the anode of the twelfth diode D12, the cathode of the twelfth diode D12 is connected to the second end of the switch control chip U1, the first end of the ninth resistor R9 is connected to the first end of the eighth resistor R8, and the second end of the ninth resistor R9 is connected to the cathode of the twelfth diode D12.

[0053] In this embodiment, the third switch Q3 is a MOS transistor.

[0054] In this embodiment, when the output of operational amplifier U2 is high, the COMP terminal of switch control chip U1 is connected to the power supply terminal VDD of the coil current switching control circuit, the OUT terminal of switch control chip U1 is high, the third switch Q3 is turned on, and the voltage of the twentieth resistor R20 gradually increases until the level of the inverting input terminal of operational amplifier U2 is greater than the level of the non-inverting input terminal. The output of operational amplifier U2 will then invert from VDD to GND, the COMP terminal of switch control chip U1 is connected to the ground terminal GND of the coil current switching control circuit, the OUT terminal of switch control chip U1 is low, the third switch Q3 is turned off, and the voltage of the twentieth resistor R20 decreases. When the level of the inverting input terminal of operational amplifier U2 is again lower than the level of the non-inverting input terminal, the COMP terminal of switch control chip U1 is connected to the power supply terminal VDD of the coil current switching control circuit, and the third switch Q3 starts working again, and so on.

[0055] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A coil current switching control circuit, characterized by, The coil current switching control circuit comprises: a signal output circuit; an operational amplifier circuit, a first end of the operational amplifier circuit being connected with a first end of the signal output circuit; a switch circuit, a first end of the switch circuit being connected with a second end of the operational amplifier circuit, the switch circuit being further used for being connected in parallel with a target coil, and a connection point of a second end of the switch circuit and a third end of the operational amplifier circuit being connected with a ground end of the coil current switching control circuit; wherein the signal output circuit outputs a first electric signal in response to a large current starting signal, the operational amplifier circuit outputs a second electric signal in response to the first electric signal, the switch circuit is turned on in response to the second electric signal, so that an end voltage of the third end of the operational amplifier circuit is raised, a third electric signal is outputted when the end voltage of the third end of the operational amplifier circuit is raised to a set voltage, and the switch circuit is turned off in response to the third electric signal.

2. The coil current switching control circuit according to claim 1, characterized in that, The signal output circuit comprises an output control chip and a voltage division control circuit; wherein a first end of the output control chip is connected with a first end of the voltage division control circuit, and a second end of the voltage division control circuit is connected with a first end of the operational amplifier circuit.

3. The coil current switching control circuit according to claim 2, characterized in that, The voltage division control circuit comprises a nineteenth resistor, a twenty-third resistor, a twenty-sixth resistor and a sixth switch tube; wherein a first end of the nineteenth resistor is connected with a power supply end of the coil current switching control circuit, a second end of the nineteenth resistor is connected with a first end of the twenty-third resistor, a second end of the twenty-third resistor is connected with a first end of the twenty-sixth resistor, a second end of the twenty-sixth resistor is connected with a ground end of the coil current switching control circuit, a gate of the sixth switch tube is connected with a first end of the output control chip, a source of the sixth switch tube is connected with a second end of the twenty-third resistor, and a drain of the sixth switch tube is connected with the first end of the twenty-third resistor.

4. The coil current switching control circuit according to claim 3, characterized by The voltage division control circuit further comprises a fifteenth capacitor, a first end of the fifteenth capacitor being connected with the source of the sixth switch tube, and a second end of the fifteenth capacitor being connected with the ground end of the coil current switching control circuit.

5. The coil current switching control circuit of claim 1, wherein, The operational amplifier circuit comprises an operational amplifier, a non-inverting input end of the operational amplifier being connected with the first end of the signal output circuit, an inverting input end of the operational amplifier being connected with the ground end of the coil current switching control circuit, and an output end of the operational amplifier being connected with the first end of the switch circuit.

6. The coil current switching control circuit of claim 5, wherein, The operational amplifier circuit further comprises an eleventh capacitor and an eighteenth resistor, the eleventh capacitor being connected between the ground end of the coil current switching control circuit and the inverting input end of the operational amplifier, and the eighteenth resistor being connected between the ground end of the coil current switching control circuit and the inverting input end of the operational amplifier.

7. The coil current commutation control circuit of claim 1, wherein, The switch circuit comprises a switch control chip and a control switch circuit; The first end of the switch control chip is connected with the second end of the operational amplifier circuit, the second end of the switch control chip is connected with the first end of the control switch circuit, and the connection point of the second end of the control switch circuit and the third end of the operational amplifier circuit is connected with the ground end of the coil current switching control circuit.

8. The coil current switching control circuit of claim 7, wherein, The control switch circuit comprises a sixth diode, a tenth diode, an eighth resistor, a ninth resistor and a third switch tube. The cathode of the sixth diode is connected with the first end of the target coil, the anode of the sixth diode is connected with the second end of the target coil, the drain of the third switch tube is connected with the anode of the sixth diode, the source of the third switch tube is connected with the ground end of the coil current switching control circuit, the gate of the third switch tube is connected with the first end of the eighth resistor, the second end of the eighth resistor is connected with the anode of the tenth diode, the cathode of the tenth diode is connected with the second end of the switch control chip, the first end of the ninth resistor is connected with the first end of the eighth resistor, and the second end of the ninth resistor is connected with the cathode of the tenth diode.

Images