Short-circuit protection circuit for electronic switch

Abstract

The invention relates to the technical field of electronic switches, in particular to an electronic switch short-circuit protection circuit which comprises an electronic switch circuit which is connected with a load in series and executes the on-off action of the load, and further comprises a first short-circuit detection circuit, a second short-circuit detection circuit and a short-circuit triggering and latching circuit which are connected with the electronic switch circuit. When a load of the electronic switching circuit is short-circuited, short-circuit voltage is generated on a switching device of the electronic switching circuit and a current detection device of the second short-circuit detection circuit, and the first short-circuit detection circuit converts the short-circuit voltage on the switching device of the electronic switching circuit into a first trigger signal of the short-circuit trigger and latch circuit; according to the short-circuit protection circuit, an electronic switch device is protected from being impacted and damaged by large current when a load is short-circuited, more importantly, the anti-interference capability of the short-circuit protection circuit is improved, misoperation is not prone to occurring, and therefore the use stability of the electronic switch is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic switches, and in particular to an electronic switch short - circuit protection circuit. Background Art

[0002] The common practice for short - circuit protection of existing electronic switches is to connect a fuse in series in the main circuit. When a short - circuit occurs in the load, the switching devices of the electronic switch will basically be damaged together; or an electronic short - circuit protection circuit is added, but in all cases, after detecting a short - circuit, the short - circuit protection circuit is triggered to turn off the switching device. Due to only a single condition of one trigger signal, it is easily interfered. Especially when there is a large - signal interference source nearby, the short - circuit circuit will malfunction, affecting the stability of the electronic switch. Summary of the Invention

[0003] The main purpose of the present invention is to provide an electronic switch short - circuit protection circuit to solve the problem in the related technology that the short - circuit protection of existing electronic switches is easily interfered due to only a single condition of one trigger signal. Especially when there is a large - signal interference source nearby, the short - circuit circuit will malfunction, affecting the stability of the electronic switch.

[0004] To achieve the above object, according to one aspect of the present invention, there is provided an electronic switch short - circuit protection circuit, including: an electronic switch circuit connected in series with a load and performing the on - off action of the load, characterized in that it further includes: a short - circuit first detection circuit, a short - circuit second detection circuit, and a short - circuit trigger and latching circuit connected to the electronic switch circuit;

[0005] Wherein the electronic switch circuit is configured to: in response to a short - circuit occurring in the load, generate a first short - circuit voltage on the switching device of the electronic switch circuit;

[0006] Wherein the short - circuit first detection circuit is configured to: convert the first short - circuit voltage on the switching device of the electronic switch circuit into a first trigger signal for the short - circuit trigger and latching circuit;

[0007] Wherein the short - circuit second detection circuit is configured to: in response to a short - circuit occurring in the load, generate a second short - circuit voltage on the current detection device of the short - circuit second detection circuit, and generate a second trigger signal required for the short - circuit trigger and latching circuit according to the second short - circuit voltage;

[0008] Wherein the short - circuit trigger and latching circuit is configured to: in response to receiving both the first trigger signal and the second trigger signal, turn off the electronic switch circuit to perform short - circuit protection.

[0009] Further, the electronic switch circuit performs the on / off operation of the load by using a rectifying device plus a switching device or the complementary manner of dual switching devices, and includes a freewheeling diode, a decoupling diode and at least one resistive device connected in parallel to the switching device.

[0010] Further, in the method of using a rectifying device plus a switching device to perform the on / off operation of the load, the second input terminal of the rectifying device is connected to one end of the load, the other end of the load is connected to the neutral wire of the mains, the first input terminal of the rectifying device is connected to the live wire of the mains, the first output terminal of the rectifying device is connected to the first current terminal of the switching device and is connected to the input terminal of the short-circuit first detection circuit, the control terminal of the switching device is connected to the output terminal of the short-circuit trigger and latch circuit and is connected to the driving circuit through a resistor, the second current terminal of the switching device is connected to the first port of the short-circuit second detection circuit, and the second output terminal of the rectifying device is connected to the second port of the short-circuit second detection circuit.

[0011] Further, in the method of using the complementary manner of dual switching devices to perform the on / off operation of the load, the first current terminal of the switching device 1 is connected to the live wire of the mains, and its second current terminal is connected to the first port of the short-circuit second detection circuit; the first current terminal of the switching device 2 is connected to one end of the load, the other end of the load is connected to the neutral wire of the mains, and the second current terminal of the switching device 2 is connected to the second port of the short-circuit second detection circuit; the first current terminals of the two switching devices are respectively connected to the input terminal of the short-circuit first detection circuit through decoupling diodes; the control terminals of the two switching devices are respectively connected to the output terminal of the short-circuit trigger and latch circuit through decoupling diodes and are respectively connected to the driving circuit through resistors; two freewheeling diodes are respectively connected in parallel to the first and second current terminals of the two switching devices.

[0012] Further, the short-circuit first detection circuit includes a short-circuit voltage sampling circuit and a voltage signal conversion circuit. When the voltage signal obtained by the short-circuit voltage sampling circuit meets the trigger signal requirement conditions of the short-circuit trigger and latch circuit, the voltage signal conversion circuit is not required and it directly serves as the first trigger signal of the short-circuit trigger and latch circuit; if not, it needs to be converted into the first trigger signal meeting the requirements of the short-circuit trigger and latch circuit through the voltage signal conversion circuit. The input terminal of the short-circuit first detection circuit is connected to the electronic switch circuit, and its output terminal is connected to the short-circuit trigger and latch circuit.

[0013] Further, the short - circuit voltage sampling circuit includes a voltage - dividing resistor device, a bypass capacitor device, and a voltage - limiting device. The short - circuit voltage sampling circuit divides the short - circuit voltage from the electronic switch circuit through the voltage - dividing resistor device, and a bypass capacitor is connected in parallel with the upper voltage - dividing resistor device to improve the sampling speed; a limiting device is connected in parallel with the lower voltage - dividing resistor device to protect the subsequent circuit.

[0014] Further, the voltage signal conversion circuit includes any one or more of an amplifying device, a comparing device, a filtering device, and a resistor device. The voltage signal conversion circuit is configured to convert the voltage signal obtained by the short - circuit voltage sampling circuit into a first trigger signal that meets the requirements of the short - circuit triggering and latching circuit.

[0015] Further, the short - circuit second detection circuit includes a current detection device and a signal processing circuit, and the signal processing circuit includes any one or more of a decoupling diode, a voltage - limiting device, an amplifying device, a comparing device, and a resistor device.

[0016] Further, the current detection device is connected in the current path of the electronic switch circuit, and the signal processing circuit is configured to generate the second trigger signal according to the voltage on the current detection device in response to the current in the current path exceeding a predetermined threshold.

[0017] Further, the short - circuit triggering and latching circuit includes a trigger signal mixing circuit, a latching circuit, and one or more of a power - supply filtering device and a decoupling diode. The first trigger signal from the short - circuit first detection circuit and the second trigger signal from the short - circuit second detection circuit are mixed into an effective trigger signal by the trigger signal mixing circuit and transmitted to the latching circuit, causing the latching circuit to act to turn off the electronic switch circuit. The short - circuit triggering and latching circuit allows an external circuit to reset and enable it, and provides the latching state to the external circuit.

[0018] Further, the trigger signal mixing circuit includes one of an analog switch, an AND gate, and a NOR gate, and includes a resistor device and a diode protection device. The trigger signal mixing circuit is configured to mix the received first trigger signal and the second trigger signal into an effective trigger signal and transmit it to the trigger circuit.

[0019] Further, the latching circuit includes one or more of a flip - flop, an amplifying device, a resistor device, and a bypass capacitor. The latching circuit is configured to perform a latching action to turn off the electronic switch circuit after receiving the trigger signal from the trigger signal mixing circuit until the latching circuit is reset.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention patent not only protects the electronic switch device from being damaged by large current impact when the load has a short circuit, but also improves the anti-interference ability of the short-circuit protection circuit, is not prone to malfunction, thereby enhancing the stability of the electronic switch in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic block diagram of the short-circuit protection circuit of the electronic switch of the present invention;

[0022] Figure 2 is the overall circuit diagram of Embodiment 1 of the present invention;

[0023] Figure 3 is the overall circuit diagram of Embodiment 2 of the present invention;

[0024] Figure 4 is the overall circuit diagram of Embodiment 3 of the present invention;

[0025] Figure 5 is the overall circuit diagram of Embodiment 4 of the present invention;

[0026] Figure 6 is the overall circuit diagram of Embodiment 5 of the present invention;

[0027] Figure 7 is the overall circuit diagram of Embodiment 6 of the present invention;

[0028] Figure 8 is the overall circuit diagram of Embodiment 7 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features, and effects according to the present invention as follows.

[0030] Please refer to Figure 1 , this embodiment provides a short-circuit protection circuit for an electronic switch. As Figure 1 shown, it includes: an electronic switch circuit connected in series with the load to perform the on-off action of the load, and further includes: a short-circuit first detection circuit, a short-circuit second detection circuit, and a short-circuit trigger and latch circuit connected to the electronic switch circuit;

[0031] A short circuit occurs in the load of the electronic switch circuit, generating a short-circuit voltage on the switching device of the electronic switch circuit and the current detection device of the second short-circuit detection circuit. The first short-circuit detection circuit converts the short-circuit voltage on the switching device of the electronic switch circuit into a first trigger signal for the short-circuit trigger and latch circuit; the second short-circuit detection circuit generates a second trigger signal required by the short-circuit trigger and latch circuit based on the short-circuit voltage on its current detection device, turns off the electronic switch circuit, and performs short-circuit protection.

[0032] Embodiment 1: As Figure 2 shown, the electronic switch circuit includes a rectifying device D9, a switching device Q1, and a resistor R4; the AC2 input terminal of the rectifying device D9 is connected to one end of the load, the other end of the load is connected to the mains zero line, the AC1 input terminal of the rectifying device D9 is connected to the mains live line, realizing the series connection of the electronic switch circuit and the load. The V+ terminal of the rectifying device D9 is connected to the drain 1 of the switching device Q1 and is connected to port 9 of the first short-circuit detection circuit through port 4. When a short circuit occurs in the load, the short-circuit voltage generated on the switching device Q1 provides a first trigger signal to the short-circuit trigger and latch circuit through the first short-circuit detection circuit.

[0033] The gate 3 of the switching device Q1 is connected to one end of the resistor R4 and is connected to port 13 of the short-circuit trigger and latch circuit through port 5. When a short circuit occurs in the load, port 13 of the short-circuit trigger and latch circuit is pulled low, and the gate 3 of the switching device Q1 is pulled low, so that the switching device Q1 is turned off, the main load circuit is cut off, and short-circuit protection is performed. The source 2 of the switching device Q1 is connected to port 6-2 of the second short-circuit detection circuit through port 3-2, and the V- terminal of the rectifying device D9 is connected to port 6-1 of the second short-circuit detection circuit through port 3-1, so that the current flowing through the switching device Q1 also flows through the second short-circuit detection circuit. When a short circuit occurs, the second short-circuit detection circuit provides a second trigger signal to the short-circuit trigger and latch circuit; the other end of the resistor R4 is externally connected to a drive signal, preventing possible damage to the drive circuit when port 13 of the short-circuit trigger and latch circuit is pulled low, and also making the turn-off of the switching device Q1 easier and more reliable.

[0034] The first short - circuit detection circuit includes a capacitor C1, a resistor R1, a resistor R2, and a zener diode D6. One end of the capacitor C1 is connected to one end of the resistor R1, and through port 9, it is connected to port 4 of the electronic switch circuit to obtain the short - circuit voltage generated on the switching device Q1 when the load is short - circuited. The other end of the capacitor C1 is connected to the other end of the resistor R1, one end of the resistor R2, and the cathode of the zener diode D6, and through port 11, it is connected to port 12 of the short - circuit trigger and latch circuit. The short - circuit voltage obtained from the switching device Q1 of the electronic switch circuit is accelerated by the capacitor C1, divided by the resistors R1 and R2, and limited by the zener diode D6, and is converted into the first trigger signal required by the short - circuit trigger and latch circuit. The other end of the resistor R2 is connected to the anode of the zener diode D6 as the common ground of the first short - circuit detection circuit, and through port 10, it is connected to the common - ground port 8 of the second short - circuit detection circuit and the common - ground port 15 of the short - circuit trigger and latch circuit.

[0035] The second short - circuit detection circuit includes a current - detecting resistor R6, a resistor R7, and a triode Q4. One end of the current - detecting resistor R6 is connected to one end of the resistor R7, and through port 6 - 2, it is connected to port 3 - 2 of the electronic switch circuit to allow the current flowing through the switching device Q1 to flow through the current - detecting resistor R6. When the load is short - circuited, a short - circuit voltage is generated on the current - detecting resistor R6. The other end of the resistor R7 is connected to the base of the triode Q4. The short - circuit voltage generated on the current - detecting resistor R6 drives the triode Q4 through R7 to make it conduct. The collector of the triode Q4 is connected to port 14 of the short - circuit trigger and latch circuit through port 7. After the triode Q4 is driven to conduct by the short - circuit voltage, it pulls down port 7 to generate the second trigger signal required by the short - circuit trigger and latch circuit. And the other end of the current - detecting resistor R6 is connected to the emitter of the triode Q4 as the common ground of the second short - circuit detection circuit, and through port 8, it is connected to the common - ground port 10 of the first short - circuit detection circuit and the common - ground port 15 of the short - circuit trigger and latch circuit, and through port 6 - 1, it is connected to port 3 - 1 of the electronic switch circuit to connect the current - detection loop.

[0036] The short - circuit trigger and latch circuit includes an analog switch U1, a D - type flip - flop U2, a protection diode D3, a pull - up resistor R8, a capacitor C2, a resistor R9, and a triode Q5.

[0037] The normally-closed pin NC of the analog switch U1 is connected to the anode of the input-terminal protection diode D3 as the input terminal of the first trigger signal, and is connected to port 11 of the short-circuit first detection circuit through port 12 to obtain the first trigger signal. The control input pin IN of the analog switch U1 is connected to one end of the pull-up resistor R8, and is connected to port 7 of the short-circuit second detection circuit through port 14. When a short circuit occurs in the load, the second trigger signal generated by the short-circuit second detection circuit pulls port 7 low, and the control input pin IN of the analog switch U1 is pulled low. The common switch pin COM of the analog switch U1 is converted from connecting the normally-open pin NO to output a low level state to connecting the normally-closed pin NC. If there is a high-level first trigger signal on the normally-closed pin NC, the common switch pin COM outputs a high level, generating a trigger signal that changes from low level to high level on the common switch pin.

[0038] The common switch pin COM of the analog switch U1 is connected to the trigger pin CP of the D flip-flop U2. The trigger signal that changes from low level to high level on the common switch pin COM triggers the D flip-flop U2 through the trigger pin CP; the data input pin D of the D flip-flop U2 is connected to the power supply pin Vcc of the D flip-flop U2, the power supply pin V+ of the analog switch U1, the other end of the pull-up resistor R8, and the cathode of the protection diode D3, and is connected to the external power supply input. After the D flip-flop U2 is triggered, its output pin Q outputs a high level. The output pin Q of the D flip-flop U2 is connected to one end of the resistor R9 and one end of the capacitor C2, and is used as a short-circuit signal output to indicate the short-circuit state to the external circuit. The other end of the resistor R9 is respectively connected to the other end of the capacitor C2 and the base of the triode Q5. The high level output by the output pin Q of the D flip-flop U2 drives the triode Q5 to conduct through the resistor R9 and the capacitor C2. The collector of the triode Q5 pulls port 13 low to turn off the switching device Q1 of the electronic switch circuit and perform short-circuit protection; the data clear pin MR of the D flip-flop U2 is externally connected to a short-circuit reset input, and the working state of the short-circuit trigger and latch circuit can be controlled by an external circuit.

[0039] The normally-closed pin of the analog switch U1 is connected to its ground pin GND, the ground pin GND of the D flip-flop U2, and the emitter of the triode Q5 as the common ground of the short-circuit trigger and latch circuit, and is connected to the common ground port 10 of the short-circuit first detection circuit and the common ground port 8 of the short-circuit second detection circuit through port 15.

[0040] Embodiment 2: As Figure 3 shown, the difference from Embodiment 1 is that:

[0041] The electronic switch circuit includes a complementary switch composed of switching devices Q1 and Q2, power-taking diodes D1, D2, driving resistors R3, R4, and diodes D4, D5, D7, D8. The complementary switch composed of Q1 and Q2 replaces the rectifying device Q9 and the switching device Q1 in Embodiment 1. The load is connected in series with Q1 and Q2 in the same loop, and the driving signals drive Q2 and Q1 through R3 and R4 respectively. The power-taking diodes D1 and D2 are respectively connected to the drains of the switching devices Q1 and Q2. When the load is short-circuited, the short-circuit voltage generated at the drains of the switching devices Q1 and Q2 is sent to the input port 9 of the short-circuit first detection circuit through D1 and D2, causing the short-circuit first detection circuit to generate a first trigger signal; the switching devices Q1 and Q2 are three-terminal devices (drain 1, source 2, gate 3). The gate 3 of Q1 is connected to one end of the resistor R4 and the anode of the diode D4, the gate 3 of Q2 is connected to one end of the resistor R3 and the anode of the diode D5, the cathodes of the diodes D4 and D5 are connected, and are connected to the port 13 of the short-circuit trigger and latch circuit through the port 5. When the load is short-circuited, the port 13 of the short-circuit trigger and latch circuit is pulled low, causing the gate 3 voltages of the switching devices Q1 and Q2 to drop, and Q1 and Q2 to turn off, thereby cutting off the main load circuit and achieving short-circuit protection. The source 2 of the switching device Q1 is connected to the port 6-2 of the short-circuit second detection circuit through the port 3-2, and the source 2 of the switching device Q2 is connected to the port 6-1 of the short-circuit second detection circuit through the port 3-1, ensuring that the current flowing through the switching devices Q1 and Q2 also flows through the short-circuit second detection circuit; when a short-circuit occurs, the short-circuit second detection circuit detects an abnormal current and provides a second trigger signal to the short-circuit trigger and latch circuit; the cathodes of the diodes D7 and D8 are respectively connected to the drains 1 of the switching devices Q1 and Q2, and the anodes of the diodes D7 and D8 are respectively connected to the sources 2 of the switching devices Q1 and Q2, enabling the electronic switch circuit to conduct alternating current.

[0042] The other ends of the resistors R3 and R4 are connected to an external driving signal for providing normal working control signals for the switching devices Q1 and Q2. When the port 13 of the short-circuit trigger and latch circuit is pulled low, R3 and R4 play a role in protecting the driving circuit, preventing the driving signal from being damaged, and at the same time making the turn-off process of Q1 and Q2 faster and more reliable due to the current-limiting effect.

[0043] The second short - circuit detection circuit includes a current - detecting resistor R6, resistors R5, R7, and transistors Q3, Q4. The current - detecting resistor R6 is connected in series in the electronic switch circuit to convert the load current into a voltage signal. The current flowing through the current - detecting resistor R6 is alternating current. Therefore, a set of short - circuit voltage detection circuits is configured at both ends of the current - detecting resistor R6 respectively to ensure that short - circuit currents in both forward and reverse directions can be detected. One set of short - circuit voltage detection circuits consists of the resistor R7 and the transistor Q4. When a short - circuit occurs in the load and the current flows in from port 6 - 2, the short - circuit voltage generated on the current - detecting resistor R6 drives the transistor Q4 to conduct through R7 to generate a second trigger signal. The other set of short - circuit voltage detection circuits consists of the resistor R5 and the transistor Q3. When a short - circuit occurs in the load and the current flows in from port 6 - 1, the short - circuit voltage generated on the current - detecting resistor R6 drives the transistor Q3 to conduct through R3 to generate a second trigger signal. The trigger signals generated by the two sets of short - circuit voltage detection circuits are both transmitted to the second trigger - signal input port 14 of the short - circuit trigger and latching circuit through port 7.

[0044] Embodiment 3: As Figure 4 shown, the difference from Embodiment 1 is that:

[0045] The second short - circuit detection circuit includes a fast comparator U3 (model TLV3201), a current - detecting resistor R6, resistors (R10, R11, R16, R17), a zener diode D10, and capacitors (C3, C5). The operational amplifier U3 is a fast comparator used for current - signal comparison and triggering. The non - inverting terminal (+) is connected to the voltage - dividing signal of resistors R10 and R11, the inverting terminal (-) is connected to the reference voltage, and the output terminal is connected to port 7. The current - detecting resistor R6 is connected in series between port 6 - 1 and 6 - 2 for current sampling. When the load current flows through R6, a voltage signal is generated. After being voltage - divided by resistors R10 and R11 and limited by the zener diode for protection, it is input to the non - inverting terminal (+) of U3. The capacitor C3 is connected in parallel across the upper voltage - dividing resistor R10 to accelerate the transmission of the voltage signal on the current - detecting resistor R6 to the non - inverting terminal (+) of the fast comparator U3. The reference voltage at the inverting terminal (-) of the fast comparator is obtained by voltage - dividing from the power supply terminal through resistors R16 and R17. The capacitor C5 is connected in parallel across the lower voltage - dividing resistor R17 to make the reference voltage clean and stable. When no short - circuit occurs, the voltage at the non - inverting terminal (+) of the fast comparator U3 is lower than the voltage at the inverting terminal (-) of the comparator, and the output terminal of the fast comparator U3 is at a low level, and port 7 is at a low level. When a short - circuit occurs, the voltage at the non - inverting terminal (+) of the fast comparator U3 is higher than the voltage at the inverting terminal (-) of the comparator, the output of the fast comparator U3 is at a high level, and port 7 outputs a second trigger signal at a high level.

[0046] The short - circuit first detection circuit includes capacitors (C1, C6), resistors (R1, R2, R18, R19), a zener diode D6, and a fast comparator U4 (model TLV3201). One end of capacitor C1 is connected to one end of resistor R1, and through port 9 to port 4 of the electronic switch circuit, for obtaining the short - circuit voltage generated on the switching devices (Q1, Q2) when the load has a short - circuit. The other end of resistor R1, one end of resistor R2, the other end of capacitor C1, and the cathode of zener diode D6 are connected together and simultaneously connected to the positive input terminal (+) of fast comparator U4. One end of resistor R18 is connected to the positive power supply of fast comparator U4, and the other end is connected to one end of R19 and one end of capacitor C6, forming a voltage reference, which is connected to the negative input terminal (-) of fast comparator U4. The output terminal of fast comparator U4 is connected to port 12 of the short - circuit trigger and latch circuit through port 11. The above - mentioned circuit constitutes a conversion of the detected short - circuit voltage signal into the first trigger signal required by the short - circuit trigger and latch circuit. Capacitor C1 is connected in parallel across resistor R1, and its function is to accelerate the transmission speed of the short - circuit voltage signal to the positive input terminal (+) of the fast comparator (U4); a zener diode is connected in parallel at the positive input terminal (+) of the fast comparator (U4), and its function is to limit the voltage signal input to the positive input terminal (+) of the fast comparator (U4), prevent excessive short - circuit voltage from damaging the operational amplifier U4, and ensure the reliability of the input signal. When there is no short - circuit, the voltage at the non - inverting terminal (+) of fast comparator U4 is lower than the voltage at the inverting terminal (-), the output terminal of fast comparator U4 is at a low level, and port 11 is at a low level; when a short - circuit occurs, the voltage at the non - inverting terminal (+) of fast comparator U4 is higher than the voltage at the inverting terminal (-), the output of fast comparator U4 is at a high level, and port 11 outputs a high - level second trigger signal. The other end of resistor R2, the anode of zener diode D6, the negative power supply of fast comparator U4, the other end of capacitor C6, and the other end of resistor R19 are connected together and through port 10 to the common - ground port 8 of the short - circuit second detection circuit and the common - ground port 15 of the short - circuit trigger and latch circuit, forming the common ground of the short - circuit first detection circuit.

[0047] In the short - circuit trigger and latch circuit, an AND gate U1 (74LVC1G08Q) is used to replace the analog switch U1 in Embodiment 1. When the electronic switch circuit is opened and there is no short - circuit, the trigger signals output by the first short - circuit detection circuit and the second short - circuit detection circuit through port 11 and port 7 are both low levels. This makes both input terminal A and input terminal B of the AND gate U1 at low levels, and the output terminal Y of the AND gate U1 outputs a low level. When a short - circuit occurs, the trigger signals output by the first short - circuit detection circuit and the second short - circuit detection circuit through port 11 and port 7 both become high levels, making both input terminal A and input terminal B of the AND gate U1 become high levels, and its output terminal changes from low level to high level. Thus, a trigger signal that changes from low level to high level is obtained to trigger the D - flip - flop to close the electronic switch circuit and latch the closed state.

[0048] Embodiment 4: As Figure 5 shown, the difference from Embodiment 1 is that:

[0049] The electronic switch circuit includes a complementary switch composed of switching devices Q1 and Q2, power - taking diodes D1, D2, driving resistors R3, R4, and diodes D4, D5, D7, D8. The complementary switch composed of Q1 and Q2 replaces the rectifying device Q9 and the switching device Q1 in Embodiment 1. The load is in series with Q1 and Q2 in the same loop, and the driving signal drives Q2 and Q1 through R3 and R4 respectively. The power - taking diodes D1 and D2 are respectively connected to the drains of the switching devices Q1 and Q2. When a short - circuit occurs in the load, the short - circuit voltage generated at the drains of the switching devices Q1 and Q2 is sent to the input port 9 of the first short - circuit detection circuit through D1 and D2, causing the first short - circuit detection circuit to generate a first trigger signal. The switching devices Q1 and Q2 are three - terminal devices (drain 1, source 2, gate 3). The gate 3 of Q1 is connected to one end of the resistor R4 and the anode of the diode D4, the gate 3 of Q2 is connected to one end of the resistor R3 and the anode of the diode D5, the cathodes of the diodes D4 and D5 are connected, and are connected to port 13 of the short - circuit trigger and latch circuit through port 5. When a short - circuit occurs in the load, port 13 of the short - circuit trigger and latch circuit is pulled low, causing the gate voltages of the switching devices Q1 and Q2 to drop, and Q1 and Q2 to turn off, thus cutting off the main load circuit and achieving short - circuit protection. The source 2 of the switching device Q1 is connected to port 6 - 2 of the second short - circuit detection circuit through port 3 - 2, and the source 2 of the switching device Q2 is connected to port 6 - 1 of the second short - circuit detection circuit through port 3 - 1, ensuring that the current flowing through the switching devices Q1 and Q2 also flows through the second short - circuit detection circuit. When a short - circuit occurs, the second short - circuit detection circuit detects the abnormal current and provides a second trigger signal to the short - circuit trigger and latch circuit.

[0050] The other ends of resistors R3 and R4 are connected to an external drive signal, which is used to provide normal operating control signals for switching devices Q1 and Q2. When the short - circuit trigger and latch circuit port 13 is pulled low, R3 and R4 play a role in protecting the drive circuit, preventing the drive signal from being damaged. At the same time, due to the current - limiting effect, the turn - off process of Q1 and Q2 becomes faster and more reliable.

[0051] The short - circuit second detection circuit uses dual current - detection resistors (R6, R6 - 1) to detect bidirectional short - circuit current, including diodes (D11, D12), resistors (R10, R11), capacitor (C3), and zener diode D10. One end of current - detection resistor R6 is connected to the anode of diode D11 and is connected to port 6 - 2 to detect the load - loop current flowing in from port 6 - 2; one end of current - detection resistor R6 - 1 is connected to the anode of diode D12 and is connected to port 6 - 1 to detect the load - loop current flowing in from port 6 - 1; the cathodes of diodes D11 and D12, one end of resistor R10, and one end of capacitor C3 are connected. No matter which port the load - loop current flows in from, when the voltage generated on the two current - detection resistors (R6, R6 - 1) is greater than the forward voltage drop of the diodes (D11, D12), it will be applied to one end of resistor R10 and one end of capacitor C3; the other end of resistor R10, the other end of capacitor C3, one end of resistor R11, and the cathode of zener diode D0 are connected. The voltage applied to one end of resistor R10 and one end of capacitor C3 is accelerated by capacitor C3, divided by resistors R10 and R11, and limited by zener diode D10, and is converted into the second trigger signal required by the short - circuit trigger and latch circuit. The other end of current - detection resistor R6, the other end of current - detection resistor R6 - 1, the other end of resistor R11, and the anode of zener diode D10 are connected as the common ground of the short - circuit second detection circuit, and are connected to the common - ground port 10 of the short - circuit first detection circuit and the common - ground port 15 of the short - circuit trigger and latch circuit through port 8.

[0052] In the short - circuit trigger and latch circuit, an AND gate U1 (74LVC1G08Q) is used to replace the analog switch U1 in Embodiment 1. After the electronic - switch circuit is turned on and no short - circuit occurs, the trigger signals output by the short - circuit first detection circuit and the short - circuit second detection circuit through port 11 and port 7 are both low levels, making both the input terminal A and input terminal B of AND gate U1 low levels, and the output terminal Y of AND gate U1 outputs a low level; when a short - circuit occurs, the trigger signals output by the short - circuit first detection circuit and the short - circuit second detection circuit through port 11 and port 7 both become high levels, making both the input terminal A and input terminal B of AND gate U1 high levels, and its output terminal changes from a low level to a high level, thus obtaining a trigger signal that changes from a low level to a high level to trigger the D - flip - flop to turn off the electronic - switch circuit and latch the off - state.

[0053] Embodiment 5: As Figure 6As shown, the difference from Embodiment 1 is that

[0054] The electronic switch circuit includes a complementary switch composed of switching devices Q1 and Q2, power-taking diodes D1, D2, driving resistors R3, R4, and diodes D4, D5, D7, D8. The complementary switch composed of Q1 and Q2 replaces the rectifying device Q9 and the switching device Q1 in Embodiment 1. The load is connected in series with Q1 and Q2 in the same loop, and the driving signal drives Q2 and Q1 through R3 and R4 respectively. The power-taking diodes D1 and D2 are respectively connected to the drains of the switching devices Q1 and Q2. When the load is short-circuited, the short-circuit voltage generated at the drains of the switching devices Q1 and Q2 is sent to the input port 9 of the short-circuit first detection circuit through D1 and D2, causing the short-circuit first detection circuit to generate a first trigger signal; the switching devices Q1 and Q2 are three-terminal devices (drain 1, source 2, gate 3). The gate 3 of Q1 is connected to one end of the resistor R4 and the anode of the diode D4, the gate 3 of Q2 is connected to one end of the resistor R3 and the anode of the diode D5, the cathodes of the diodes D4 and D5 are connected, and are connected to the port 13 of the short-circuit trigger and latch circuit through the port 5. When the load is short-circuited, the port 13 of the short-circuit trigger and latch circuit is pulled low, resulting in a decrease in the gate 3 voltage of the switching devices Q1 and Q2, and Q1 and Q2 are turned off, thus cutting off the main load circuit to achieve short-circuit protection. The source 2 of the switching device Q1 is connected to the port 6-2 of the short-circuit second detection circuit through the port 3-2, and the source 2 of the switching device Q2 is connected to the port 6-1 of the short-circuit second detection circuit through the port 3-1, ensuring that the current flowing through the switching devices Q1 and Q2 also flows through the short-circuit second detection circuit; when a short-circuit occurs, the short-circuit second detection circuit detects an abnormal current and provides a second trigger signal to the short-circuit trigger and latch circuit.

[0055] The other ends of the resistors R3 and R4 are connected to an external driving signal for providing normal operating control signals for the switching devices Q1 and Q2. When the port 13 of the short-circuit trigger and latch circuit is pulled low, R3 and R4 play a role in protecting the driving circuit, preventing the driving signal from being damaged, and at the same time making the turn-off process of Q1 and Q2 faster and more reliable due to the current-limiting effect.

[0056] The diode D6 in the short-circuit first detection circuit is replaced by a triode Q6, and the resistors R1 and R2 change from a voltage-dividing function to a current-limiting and current-splitting function. When a short-circuit occurs, the short-circuit voltage generated on the switching devices (Q1, Q2) is applied to the base of the triode Q6 through the current-limiting resistor R1, causing it to conduct and pull the port 11 low. The resistor R2 plays a role in splitting the current flowing into the base of the triode Q6 to adjust the input impedance of the base of the triode Q6, improving stability and reliability, and can also adjust the detection sensitivity. The triode Q6 can amplify tiny currents and has higher sensitivity, suitable for weak signal detection.

[0057] The short - circuit second detection circuit adds a set of reverse - current detection circuits to ensure that both the forward and reverse currents in the load circuit can be detected. It adds a resistor R5 and a triode Q3. One end of the resistor R5 is connected to the common ground; the emitter of the triode Q3 is connected to one end of the current - detection resistor R6 and the connection port 6 - 2; the other end of the resistor R5 is connected to the base of the triode Q3; the collector of the triode Q3 is connected to the port 7. When the current flows in from the port 6 - 1, a voltage is generated at the end of the current - detection resistor R6 connected to the common ground. The resistor R5 drives the triode Q3 to conduct, pulling down the port 7 and outputting a second trigger signal.

[0058] In the short - circuit trigger and latch circuit, a NOR gate U1 (74LVC1G02) is used to replace the analog switch U1 in Embodiment 1. After the electronic switch circuit is turned on and there is no short - circuit, the ports 11 and 7 of the short - circuit first detection circuit and the short - circuit second detection circuit are in a released state. The two input terminals A and B of the NOR gate U1 are set to the high - level state by two pull - up resistors R12 and R8 respectively, and the output terminal Y of the NOR gate U1 outputs a low level. When a short - circuit occurs, the short - circuit first detection circuit and the short - circuit second detection circuit pull down the ports 11 and 7 respectively. The two input terminals A and B of the NOR gate U1 both become low levels, and its output terminal changes from low level to high level, thus obtaining a trigger signal that changes from low level to high level to trigger the D - flip - flop to turn off the electronic switch circuit and latch the off - state.

[0059] Embodiment 6: As Figure 7 shown, the difference from Embodiment 1 is that:

[0060] The electronic switch circuit includes a complementary switch composed of switching devices Q1 and Q2, power-taking diodes D1, D2, driving resistors R3, R4, and diodes D4, D5, D7, D8. The complementary switch composed of Q1 and Q2 replaces the rectifying device Q9 and the switching device Q1 in Embodiment 1. The load is connected in series with Q1 and Q2 in the same loop, and the driving signal drives Q2 and Q1 through R3 and R4 respectively. The power-taking diodes D1 and D2 are respectively connected to the drains of the switching devices Q1 and Q2. When the load is short-circuited, the short-circuit voltage generated at the drains of the switching devices Q1 and Q2 is sent to the input port 9 of the first short-circuit detection circuit through D1 and D2, causing the first short-circuit detection circuit to generate a first trigger signal; the switching devices Q1 and Q2 are three-terminal devices (drain 1, source 2, gate 3). The gate 3 of Q1 is connected to one end of the resistor R4 and the anode of the diode D4, the gate 3 of Q2 is connected to one end of the resistor R3 and the anode of the diode D5, the cathodes of the diodes D4 and D5 are connected, and are connected to the port 13 of the short-circuit trigger and latch circuit through the port 5. When the load is short-circuited, the port 13 of the short-circuit trigger and latch circuit is pulled low, causing the gate 3 voltages of the switching devices Q1 and Q2 to drop, and Q1 and Q2 to turn off, thereby cutting off the main load circuit and achieving short-circuit protection. The source 2 of the switching device Q1 is connected to the port 6-2 of the second short-circuit detection circuit through the port 3-2, and the source 2 of the switching device Q2 is connected to the port 6-1 of the second short-circuit detection circuit through the port 3-1, ensuring that the current flowing through the switching devices Q1 and Q2 also flows through the second short-circuit detection circuit; when a short circuit occurs, the second short-circuit detection circuit detects an abnormal current and provides a second trigger signal to the short-circuit trigger and latch circuit; the cathodes of the diodes D7 and D8 are respectively connected to the drains 1 of the switching devices Q1 and Q2, and the anodes of the diodes D7 and D8 are respectively connected to the sources 2 of the switching devices Q1 and Q2, enabling the electronic switch circuit to conduct alternating current.

[0061] The other ends of the resistors R3 and R4 are connected to an external driving signal for providing normal operating control signals for the switching devices Q1 and Q2. When the port 13 of the short-circuit trigger and latch circuit is pulled low, R3 and R4 play a role in protecting the driving circuit, preventing the driving signal from being damaged, and at the same time making the turn-off process of Q1 and Q2 faster and more reliable due to the current-limiting effect.

[0062] The diode D6 in the first short-circuit detection circuit is replaced by a triode Q6, and the resistors R1 and R2 change from a voltage-dividing function to a current-limiting and current-splitting function. When a short circuit occurs, the short-circuit voltage generated on the switching devices (Q1, Q2) is applied to the base of the triode Q6 through the current-limiting resistor R1, causing it to conduct and pulling the port 11 low. The resistor R2 plays a role in splitting the current flowing into the base of the triode Q6 to adjust the input impedance of the base of the triode Q6, improving stability and reliability, and can also adjust the detection sensitivity. The triode Q6 can amplify tiny currents, has higher sensitivity, and is suitable for weak signal detection.

[0063] The short - circuit second detection circuit adds a set of reverse - current detection circuits to ensure that both the forward and reverse currents in the load loop can be detected. It adds a resistor R5 and a triode Q3. One end of the resistor R5 is connected to the common ground, and the other end is connected to the base of the triode Q3; the emitter of the triode Q3 is connected to one end of the current - detection resistor R6 and the connection port 6 - 2; the other end of the resistor R5 is connected to the base of the triode Q3; the collector of the triode Q3 is connected to the port 7. When the current flows in from the port 6 - 1, a voltage is generated at the end of the current - detection resistor R6 connected to the common ground. The triode Q3 is driven to conduct through the resistor R5, pulling down the port 7 and outputting the second trigger signal.

[0064] The short - circuit trigger and latch circuit includes a NOR gate U1 (74LVC1G02), transistors (Q7, Q8), resistors (R8, R9, R12, R13, R14, R15), capacitors (C2, C4), diode D14, and zener diode D13. One end of resistor R8 is connected to the input terminal B and port 14 of NOR gate U1. One end of resistor R12 is connected to the input terminal A and port 12 of NOR gate U1. The other end of resistor R8 is connected to the other end of resistor R12 and the power supply terminal VCC of NOR gate U1. Resistors R8 and R12 implement the pull - up function for the two input terminals of NOR gate U1, so that the output terminal Y of NOR gate U1 outputs a low level under normal conditions. After the electronic switch circuit is turned on and there is no short - circuit, ports 11 and 7 of the first short - circuit detection circuit and the second short - circuit detection circuit are in a released state. The two input terminals A and B of NOR gate U1 are respectively set to a high - level state by two pull - up resistors R12 and R8, and the output terminal Y of NOR gate U1 outputs a low level. When a short - circuit occurs, the first short - circuit detection circuit and the second short - circuit detection circuit respectively pull down ports 11 and 7. The two input terminals A and B of NOR gate U1 both become low levels, and its output terminal changes from a low level to a high level, thus obtaining a trigger signal that changes from a low level to a high level. Transistor Q7 is of PNP type, and transistor Q8 is of NPN type. The collector of transistor Q7 is connected to the base of transistor Q8, one end of resistor R9, and one end of capacitor C2, and is externally connected to a short - circuit reset input, which is usually in a high - impedance state and needs to be pulled low for resetting. The base of transistor Q7 is connected to the collector of transistor Q8, one end of resistor R15, the cathode of diode D14, and port 13. The emitter of transistor Q7 is connected to one end of resistor R14. The other end of resistor R9 is connected to the other end of capacitor C2 and the output terminal of NOR gate U1. The other end of resistor R14 is connected to the other end of resistor R15 and one end of resistor R13, and is connected to an external power supply input. The other end of resistor R13 is connected to one end of capacitor C4 and the cathode of zener diode D13, and is connected to the power supply terminal Vcc of NOR gate U1. The ground terminal GND of NOR gate U1 is connected to the emitter of transistor Q8 to form the common ground of the short - circuit trigger and latch circuit, and is connected to the common ground port 10 of the first short - circuit detection circuit and the common ground port 8 of the second short - circuit detection circuit through port 15. The anode of diode D14 is used as the short - circuit signal output terminal. Under normal conditions, if the external circuit has a pull - up, this short - circuit signal output terminal is in a high - level state, and is pulled low to the conduction voltage drop of transistor Q8 plus the forward voltage drop of diode D14 in the short - circuit latch state.The triodes Q7 and Q8 form a self-latching circuit. When the output terminal Y of the NOR gate U1 changes from low level to high level, the high-level signal drives the triode Q8 to conduct through the resistor R9. When the triode Q8 conducts, it pulls down the base of the triode Q7 to make the triode Q7 conduct. When the triode Q7 conducts, the base of the triode Q8 gets a bias current to maintain the conduction of Q8, realizing the latching of the conduction states of the two triodes (Q7, Q8). At this time, even if the output terminal Y of the NOR gate U1 changes from high level to low level, the two triodes (Q7, Q8) still maintain the conduction state and will not turn off until they are reset by the short-circuit reset input signal and exit the conduction latching state. After the triode Q8 conducts, it pulls down and maintains port 13, thereby turning off the switching devices (Q1, Q2) of the electronic switch circuit to achieve short-circuit protection. The capacitor C2 is connected in parallel across the resistor R9, and its function is to accelerate the transmission of the high-level signal output from the output terminal Y of the NOR gate U1 to the base of the triode Q8, shortening the short-circuit latching response time and improving the reliability of short-circuit protection. The resistors R13, capacitor C4, and zener diode D13 constitute a secondary power supply for resistor voltage reduction to supply power to the NOR gate U1.

[0065] Embodiment 7: As Figure 8 shown, the difference from Embodiment 1 is that:

[0066] The second short-circuit detection circuit includes a current detection resistor R6, voltage-dividing resistors R10, R11, a capacitor C3, and a zener diode D10. The current detection resistor R6 is connected in series between port 6-1 and 6-2 to directly detect the load loop current. One end of the voltage-dividing resistor R10 is connected to one end of R6, one end of the capacitor C3, and port 6-2, and the other end is connected to the cathode of the zener diode D10, one end of the voltage-dividing resistor R11, the other end of the capacitor C3, and port 7. The other end of the current detection resistor R6 is connected to the other end of the voltage-dividing resistor R11 and the anode of the zener diode to form the common ground of the second short-circuit detection circuit. It is connected to the common ground port 10 of the first short-circuit detection circuit and the common ground port 15 of the short-circuit trigger and latching circuit through port 8, and is connected to the electronic switch circuit port 3-1 through port 6-1 to connect the current detection loop. The current flowing in from port 6-2 generates a voltage across the detection resistor R6, and the voltage signal is divided by the voltage-dividing resistors R10 and R11 and provided as the second trigger signal to the short-circuit trigger and latching circuit through port 7. The capacitor C3 is connected in parallel across the upper voltage-dividing resistor R10 to accelerate the transmission of the voltage signal to port 7 and improve the response speed to the voltage signal. The zener diode is connected in parallel across the lower voltage-dividing resistor R11 to limit the voltage at port 7 and prevent voltage overshoot from damaging the short-circuit trigger and latching circuit.

[0067] In the short - circuit trigger and latch circuit, an AND gate U1 (74LVC1G08Q) is used to replace the analog switch U1 in Embodiment 1. When the electronic switch circuit opens the barrel and there is no short - circuit, the trigger signals output by the first short - circuit detection circuit and the second short - circuit detection circuit through port 11 and port 7 are both low levels, making the input terminal A and input terminal B of the AND gate U1 both at low levels, and the output terminal Y of the AND gate U1 outputs a low level. When a short - circuit occurs, the trigger signals output by the first short - circuit detection circuit and the second short - circuit detection circuit through port 11 and port 7 both become high levels, making the input terminal A and input terminal B of the AND gate U1 both become high levels, and its output terminal changes from low level to high level, thereby obtaining a trigger signal that changes from low level to high level to trigger the D - flip - flop to close the electronic switch circuit and latch the closed state.

[0068] As described above, it is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to it as equivalent embodiments within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An electronic switch short-circuit protection circuit, comprising: An electronic switch circuit connected in series with a load and performing an on / off operation of the load, characterized by further comprising: a short-circuit first detection circuit, a short-circuit second detection circuit, and a short-circuit trigger and latching circuit connected to the electronic switch circuit; Wherein the electronic switch circuit is configured to: in response to a short circuit occurring in the load, generate a first short-circuit voltage on a switching device of the electronic switch circuit; Wherein the short-circuit first detection circuit is configured to: convert the first short-circuit voltage on the switching device of the electronic switch circuit into a first trigger signal for the short-circuit trigger and latching circuit; Wherein the short-circuit second detection circuit is configured to: in response to a short circuit occurring in the load, generate a second short-circuit voltage on a current detection device of the short-circuit second detection circuit, and generate a second trigger signal required for the short-circuit trigger and latching circuit according to the second short-circuit voltage; Wherein the short-circuit trigger and latching circuit is configured to: in response to receiving both the first trigger signal and the second trigger signal, turn off the electronic switch circuit to perform short-circuit protection.

2. The short-circuit protection circuit for an electronic switch according to claim 1, characterized in that, The electronic switch circuit adopts a complementary manner of a rectifying device (D9) plus a switching device (Q1) or a dual switching device (Q1, Q2) to perform the on / off operation of the load, including freewheeling diodes (D7, D8), decoupling diodes (D1, D2, D4, D5), and at least one resistive device (R3, R4) connected in parallel to the switching device (Q1, Q2).

3. The short-circuit protection circuit of the electronic switch according to claim 2, characterized in that, A second input terminal of the rectifying device (D9) is connected to one end of the load, the other end of the load is connected to the mains neutral line, a first input terminal of the rectifying device (D9) is connected to the mains live line, a first output terminal of the rectifying device (D9) is connected to a first current terminal of the switching device and is connected to an input terminal of the short-circuit first detection circuit, a control terminal of the switching device is connected to an output terminal of the short-circuit trigger and latching circuit, and is connected to a driving circuit through a resistor (R4), a second current terminal of the switching device is connected to a first port of the short-circuit second detection circuit, and a second output terminal of the rectifying device is connected to a second port of the short-circuit second detection circuit.

4. The electronic switch short-circuit protection circuit according to claim 2, characterized in that, A first current terminal of the switching device 1 (Q1) is connected to the mains live line, and its second current terminal is connected to a first port of the short-circuit second detection circuit; a first current terminal of the switching device 2 (Q2) is connected to one end of the load, the other end of the load is connected to the mains neutral line, and a second current terminal of the switching device 2 (Q2) is connected to a second port of the short-circuit second detection circuit; first current terminals of the two switching devices (Q1, Q2) are respectively connected to an input terminal of the short-circuit first detection circuit through decoupling diodes (D2, D1); control terminals of the two switching devices (Q1, Q2) are respectively connected to an output terminal of the short-circuit trigger and latching circuit through decoupling diodes (D4, D5), and are respectively connected to a driving circuit through resistors (R4, R3); two freewheeling diodes (D7, D8) are respectively connected in parallel to the first and second current terminals of the two switching devices (Q1, Q2).

5. The short-circuit protection circuit for an electronic switch according to claim 1, wherein The first short - circuit detection circuit includes a short - circuit voltage sampling circuit and a voltage signal conversion circuit. When the voltage signal obtained by the short - circuit voltage sampling circuit meets the trigger signal requirement conditions of the short - circuit trigger and latching circuit, the voltage signal conversion circuit is not required, and it directly serves as the first trigger signal of the short - circuit trigger and latching circuit; if not, it needs to be converted by the voltage signal conversion circuit into the first trigger signal meeting the requirements of the short - circuit trigger and latching circuit. The input end of the first short - circuit detection circuit is connected to the electronic switch circuit, and its output end is connected to the short - circuit trigger and latching circuit.

6. The electronic switch short-circuit protection circuit according to claim 5, wherein, The short - circuit voltage sampling circuit includes voltage - dividing resistor devices (R1, R2), bypass capacitor devices (C2), and voltage - limiting devices (D6). The short - circuit voltage sampling circuit divides the short - circuit voltage from the electronic switch circuit through the voltage - dividing resistor devices (R1, R2). A bypass capacitor (C1) is connected in parallel to the upper voltage - dividing resistor device (R1) to improve the sampling speed; a limiting device (D6) is connected in parallel to the lower voltage - dividing resistor device (R2) to protect the subsequent circuit.

7. The short - circuit protection circuit for an electronic switch according to claim 5, characterized in that, The voltage signal conversion circuit includes any one or more of an amplifying device (Q6), a comparing device (U4), a capacitor device (C6), and resistor devices (R18, R19). The voltage signal conversion circuit is configured to convert the voltage signal obtained by the short - circuit voltage sampling circuit into the first trigger signal meeting the requirements of the short - circuit trigger and latching circuit.

8. The short-circuit protection circuit of the electronic switch according to claim 1, wherein The second short - circuit detection circuit includes a current - detecting device (R6) and a signal - processing circuit. The signal - processing circuit includes any one or more of decoupling diodes (D11, D12), voltage - limiting devices (D10), amplifying devices (Q3, Q4), comparing devices (U3), capacitor devices (C3, C5), and resistor devices (R5, R7, R10, R11, R16, R17).

9. The electronic switch short-circuit protection circuit according to claim 8, characterized in that, The current - detecting device (R6) is connected in the current path of the electronic switch circuit, and the signal - processing circuit is configured to generate the second trigger signal according to the voltage on the current - detecting device (R6) in response to the current in the current path exceeding a predetermined threshold.

10. The short-circuit protection circuit of the electronic switch according to claim 1, characterized in that, The short - circuit trigger and latching circuit includes a trigger - signal mixing circuit, a latching circuit, and any one or more of power - supply filtering devices (R13, C4, D13), decoupling diodes (D14). The first trigger signal from the first short - circuit detection circuit and the second trigger signal from the second short - circuit detection circuit are mixed into an effective trigger signal by the trigger - signal mixing circuit and transmitted to the latching circuit, causing the latching circuit to act to turn off the electronic switch circuit. The short - circuit trigger and latching circuit allows an external circuit to reset and enable it and provides the latching state to the external circuit.

11. The short-circuit protection circuit for an electronic switch according to claim 10, characterized in that, The trigger signal mixing circuit includes one of an analog switch, an AND gate, and a NOR gate, and includes resistor devices (R8, R12) and a diode protection device (D3). The trigger signal mixing circuit is configured to mix the received first trigger signal and the second trigger signal into an effective trigger signal and deliver it to the trigger circuit.

12. The electronic switch short-circuit protection circuit according to claim 10, wherein The latching circuit includes one or more of a flip-flop (U2), amplifying devices (Q5, Q7, Q8), resistor devices (R9, R14, R15), and a bypass capacitor (C2). The latching circuit is configured to perform a latching action to turn off the electronic switch circuit after receiving the trigger signal from the trigger signal mixing circuit until the latching circuit is reset.

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