TW202332156A - Electric circuit protection device - Google Patents

Abstract

The electric circuit protection device of the invention comprises a first semiconductor, a second semiconductor, a third semiconductor, a first resistor, a second resistor, a third resistor, a first diode and a voltage comparator, constituting an application circuit with load overload or short circuit protection function, which avoids the damage caused by overload or short circuit at both terminals of the load.

Description

circuit protection device

The circuit protection device of the present invention belongs to the electronic technical field with the function of protecting the DC power supply when overload or short circuit occurs at both ends of the load in the application process of the DC circuit.

The circuit protection device of the present invention has been searched by the inventor for related circuit protection devices and related invention documents of the circuit protection device, and the same or similar technology as the circuit protection device of the present invention has not been found, especially the third semiconductor and the second resistor of the present invention The self-locking circuit technology means composed of a voltage regulator and a voltage comparator can achieve the function of protecting the DC power supply when overload or short circuit occurs at both ends of the load during the application of the DC circuit. It is the first invention in the world. Other circuit features are all It is described in detail in the specification of the present invention.

Purpose of the present invention:

The present invention applies the first semiconductor, the second semiconductor, the third semiconductor, the first resistor, the second resistor, the third resistor, the first diode and The voltage comparator can protect the DC power supply when the load overload or short circuit occurs in the DC circuit power supply.

When the load is short-circuited, the present invention uses the first semiconductor to perform an open-circuit operation in a very short time, so as to protect the DC power supply circuit and avoid various disasters caused by the short-circuit of the load.

The first semiconductor of the present invention enables the load to receive power from the DC power supply when the invention is started, and prevents the load from receiving power from the DC power supply when the invention is shut down.

In the present invention, when starting up, the conduction of the first semiconductor is that the gate of the first semiconductor is supplied with voltage by the second power supply.

The present invention has following characteristics:

1. The feature of the first semiconductor of the present invention is that it is responsible for the open circuit and conduction of the DC power supply to supply power to the load.

2. The present invention is provided with a second semiconductor. When the second power supply is supplied to the gate of the second semiconductor, the drain and source of the second semiconductor are turned on, and the drain voltage of the first semiconductor passes through the drain and source of the second semiconductor. The source reaches the positive input terminal of the voltage comparator. When the second power supply does not supply power to the gate of the second semiconductor, the drain and source of the second semiconductor are open, and the drain voltage of the first semiconductor does not reach the voltage comparator. The positive input.

3. The third semiconductor of the present invention is responsible for controlling the open-circuit action of the first semiconductor, so as to protect the DC power supply circuit when a short circuit occurs at both ends of the load.

4. In the present invention, the circuit composed of the second resistor, the third semiconductor and the voltage comparator has the function of interlock.

5. In the present invention, the first resistor has the function of limiting the current to prevent the first semiconductor from being damaged due to excessive gate current.

6. In the present invention, the second resistor has the function of limiting the current, so as to prevent the third semiconductor from being damaged due to excessive drain-source current.

7. The present invention provides a third resistor so that the positive input terminal of the voltage comparator is at the same potential as the negative power supply terminal of the voltage comparator in normal times.

8. The present invention is provided with a first diode to separate the first power supply from the second power supply, and the first power supply does not supply power to the circuit to which the second power supply belongs.

9. The first semiconductor of the present invention includes both N Channel Metal Oxide Semiconductor Field Effect Transistor (N Channel MOSFET) and Insulated Gate Bipolar Transistor (IGBT) You can choose according to your needs.

10. The second semiconductor of the present invention includes N-channel metal oxide semiconductor field effect transistor and insulated gate bipolar transistor, both of which can be selected according to requirements.

11. The third semiconductor of the present invention includes N-channel metal oxide semiconductor field effect transistor and insulated gate bipolar transistor, both of which can be selected according to requirements.

12. The fourth semiconductor of the present invention is a P-channel metal oxide semiconductor field effect transistor.

10: load

11: The first power supply

12: Second power supply

13: The third power supply

14: DC power supply

15: Negative input terminal of voltage comparator

16: Positive input terminal of voltage comparator

17: The output terminal of the voltage comparator

18: First resistor

19: Second resistor

20: Voltage comparator

21:First Semiconductor

22:Second semiconductor

23: The third semiconductor

24: The first diode

25: Third resistor

26: The first voltage divider resistor

27: Second voltage divider resistor

28: Fourth Semiconductor

29: Resistance sensor

Fig. 1 is the first embodiment of the circuit protection device of the present invention.

Fig. 2 is the second embodiment of the circuit protection device of the present invention.

Fig. 3 is the third embodiment of the circuit protection device of the present invention.

Fig. 4 is the fourth embodiment of the circuit protection device of the present invention.

Fig. 5 is the fifth embodiment of the circuit protection device of the present invention.

Fig. 6 is the sixth embodiment of the circuit protection device of the present invention.

Fig. 7 is the seventh embodiment of the circuit protection device of the present invention.

As shown in Figure 1, it is the first embodiment of the circuit protection device of the present invention, As can be seen from the figure, the circuit protection device of the present invention includes a first semiconductor 21, a second semiconductor 22, a third semiconductor 23, a first resistor 18, a second resistor 19, a third resistor 25, a first diode 24 and voltage comparator 20.

The positive end of the DC power supply 14 is connected to the first end of the load 10, the second end of the load 10 is connected to the drain D (Drain, D) of the first semiconductor 21, and the source S (Source, S) of the first semiconductor 21 is connected to The negative terminal of the DC power supply 14 and the negative terminal of the voltage comparator 20 .

The gate G (Gate, G) of the first semiconductor 21 is connected to the second end of the first resistor 18, the gate G of the second semiconductor 22 and the anode end of the first diode 24, and the second end of the first resistor 18 One end is connected to the second power supply 12 .

The positive input terminal (Non-inverting Input) 15 of the voltage comparator 20 is connected to the source S of the second semiconductor 22, the source S of the third semiconductor 23 and the first end of the third resistor 25, and the first end of the third resistor 25 The second end is connected to the negative power supply terminal of the voltage comparator 20, and the negative input terminal (Inverting Input) 16 of the voltage comparator 20 is connected to the third power supply 13, and the third power supply 13 is the reference voltage of the negative input terminal 16 of the voltage comparator 20 ( Reference Voltage), the positive power supply terminal of the voltage comparator 20 is connected to the first power supply 11.

The drain D of the second semiconductor 22 is connected to the drain D of the first semiconductor 21 .

The output terminal 17 of the voltage comparator 20 is connected to the gate G of the third semiconductor 23 .

The cathode end of the first diode 24 is connected to the drain D of the third semiconductor 23 and the second end of the second resistor 19, and the first end of the second resistor 19 is connected to the positive power end of the voltage comparator 20. power supply11.

As shown in FIG. 1, when both ends of the load 10 are short-circuited, according to the output characteristic curve table (Output Characteristics) of the first semiconductor 21, it can be known that when the drain current of the first semiconductor 21 rises to its corresponding drain current The source voltage (Drain Source Voltage) passes through the second semiconductor The drain D and the source S of the body 22 reach the positive input terminal 15 of the voltage comparator 20. When the voltage of the positive input terminal 15 of the voltage comparator 20 is higher than the reference voltage of the negative input terminal 16 of the voltage comparator 20, the voltage comparison The output terminal 17 of the device 20 outputs a positive voltage to supply power to the gate G of the third semiconductor 23. At this time, the drain D and the source S of the third semiconductor 23 are turned on (Turn On), and the drain D and the source S of the first semiconductor 21 are turned on. The source S is open (Turn Off), and the drain D and source S of the second semiconductor 22 are open, and the drain D and source S of the first semiconductor 21 are open, and the DC power supply 14 does not supply power to the short-circuit load 10, so that The DC power supply 14 is protected; in the same way, proper selection of the conduction voltage value between the drain D and the source S of the second semiconductor 22 and the reference voltage value of the negative input terminal 16 of the voltage comparator 20 can also achieve overload protection function.

When the output terminal 17 of the voltage comparator 20 outputs a positive voltage to supply power to the gate G of the third semiconductor 23, the drain D and the source S of the third semiconductor 23 are turned on, and the first power supply 11 supplies power to the second resistor 19, through the drain pole D and the source pole S of the third semiconductor 23, power is supplied to the positive input terminal 15 of the voltage comparator 20, and the function of self-locking is generated, so that the output terminal 17 of the voltage comparator 20 is maintained to output a positive voltage, and at the same time Because the drain D and the source S of the third semiconductor 23 are turned on, the drain D and the source S of the first semiconductor 21 are opened, thereby achieving the function of protecting the DC power supply 14 .

When the output terminal 17 of the voltage comparator 20 outputs a positive voltage to supply power to the gate G of the third semiconductor 23, the drain D and the source S of the third semiconductor 23 are turned on, and the drain D and the source of the first semiconductor 21 The pole S is open, which means that the first semiconductor 21 has a self-protection function.

As shown in FIG. 2, it is the second embodiment of the circuit protection device of the present invention. It can be seen from the figure that the first semiconductor 21, the second semiconductor 22 and the third semiconductor 23 in FIG. The effective transistor is changed to an insulated gate bipolar transistor, and other circuit structures are the same as those in Figure 1 The same without repeating.

As shown in FIG. 2, when both ends of the load 10 are short-circuited, according to the output characteristic curve table of the first semiconductor 21, when the collector current (Collector Current) of the first semiconductor 21 rises to its corresponding collector-emitter voltage ( Collector Emitter Voltage) reaches the positive input terminal 15 of the voltage comparator 20 through the collector C and the emitter E of the second semiconductor 22, when the voltage of the positive input terminal 15 of the voltage comparator 20 is higher than the negative input terminal 16 of the voltage comparator 20 When the reference voltage is lower than the reference voltage, the output terminal 17 of the voltage comparator 20 outputs a positive voltage to supply power to the gate G of the third semiconductor 23. At this time, the collector C and the emitter E of the third semiconductor 23 are turned on, and the collector of the first semiconductor 21 The pole C and the emitter E are open, and the collector C and the emitter E of the second semiconductor 22 are open. Because the collector C and the emitter E of the first semiconductor 21 are open, the DC power supply 14 does not supply power to the short-circuit load 10, so that The DC power supply 14 is protected; in the same way, the collector-emitter voltage value between the collector C and the emitter E of the first semiconductor 21 and the collector-emitter voltage between the collector C and the emitter E of the second semiconductor 22 are properly selected Value, with the reference voltage value of the negative input terminal 16 of the voltage comparator 20 can also achieve the function of overload protection.

When the output terminal 17 of the voltage comparator 20 outputs a positive voltage to supply power to the gate G of the third semiconductor 23, the collector C and the emitter E of the third semiconductor 23 are turned on, and the first power supply 11 supplies power to the second resistor 19, through the collector C and the emitter E of the third semiconductor 23, power is supplied to the positive input terminal 15 of the voltage comparator 20, and the function of self-locking is generated, so that the output terminal 17 of the voltage comparator 20 is maintained to output a positive voltage, and at the same time Because the collector C and the emitter E of the third semiconductor 23 are turned on, the collector C and the emitter E of the first semiconductor 21 are opened, thereby achieving the function of protecting the DC power supply 14 .

From the above, it can be known that in FIG. 2, the first semiconductor 21, the second semiconductor 22 and the third semiconductor 23 in FIG. 1 are changed from N-channel metal oxide semiconductor field effect transistors to insulated gate bipolar transistors, and the operating principle is the same. And the function of protecting the DC power supply 14 when its load 10 is short-circuited is also the same.

As can be seen from the above, the first semiconductor 21, the second semiconductor 22 and the third semiconductor 23 in FIGS. 1 and the first semiconductor 21, the second semiconductor 22 and the third semiconductor 23 in FIG. The effective transistor is replaced by an insulated gate bipolar transistor, which can be selected according to its needs without self-limitation.

As shown in Figure 3, it is the third embodiment of the circuit protection device of the present invention. It can be seen from the figure that the first voltage dividing resistor is connected between the drain D and the source S of the first semiconductor 21 in Figure 1 (First Divider Resistor) 26 and the second divider resistor (Second Divider Resistor) 27, the first end of the first divider resistor 26 is connected to the drain D of the first semiconductor 21, and the second divider resistor 27 The second end of the first semiconductor 21 is connected to the source S, the second end of the first voltage dividing resistor 26 is connected to the first end of the second voltage dividing resistor 27 and the drain D of the second semiconductor 22, the second The source S of the semiconductor 22 is connected to the positive input terminal of the voltage comparator 20, and other circuit structures are the same as those in FIG. 1 and will not be repeated.

As shown in Figure 3, it can be seen from the figure that when both ends of the load 10 are short-circuited, the drain current of the first semiconductor 21 rises, and the voltage across the drain D and source S of the first semiconductor 21 is supplied to the first voltage dividing resistor A series circuit of the device 26 and the second voltage-dividing resistor 27, the first voltage-dividing resistor 26 and the second voltage-dividing resistor 27 are connected in series to the midpoint voltage, through the drain D and the source S of the second semiconductor 22 Reach the positive input terminal 15 of the voltage comparator 20, when the positive input terminal 15 voltage of the voltage comparator 20 is higher than the reference voltage supplied by the third power supply 13 of the negative input terminal 16 of the voltage comparator 20, the voltage comparator 20 The output terminal 17 outputs a positive voltage to supply power to the gate G of the third semiconductor 23, so that the drain D and the source S of the third semiconductor 23 are turned on. At this time, the drain D and the source S of the first semiconductor 21 are open. and The purpose of protecting the DC power supply 14 is achieved.

As shown in Figure 4, it is the fourth embodiment of the circuit protection device of the present invention. As can be seen from the figure, it changes the second semiconductor 22 circuit in Figure 3 into a fourth semiconductor 28 circuit with the same function, and other circuit structures are all the same as Figure 3 is the same and will not be repeated.

As shown in Figure 4, it can be known from Figure 4 that the second semiconductor 22 is an N channel metal oxide semiconductor field effect transistor, the fourth semiconductor 28 is a P channel metal oxide semiconductor field effect transistor (P Channel MOSFET), and the fourth semiconductor The source S of 28 is connected to the positive input terminal 15 of the voltage comparator 20, the drain D of the fourth semiconductor 28 is connected to the negative power supply terminal of the voltage comparator 20, and the gate G of the fourth semiconductor 28 is connected to the gate of the first semiconductor 21 g.

As shown in Figure 4, it can be seen from the figure that when the drain D and the source S of the third semiconductor 23 are open, the drain D and the source S of the fourth semiconductor 28 are open, and when the drain D of the third semiconductor 23 is open. When conducting with the source S, the drain D of the fourth semiconductor 28 is conducting with the source S, and other action principles for protecting the DC power supply 14 when the load 10 is short-circuited are the same as those in FIG. 3 and will not be repeated here.

As shown in Figure 5, it is the fifth embodiment of the circuit protection device of the present invention. As can be seen from the figure, it changes the second semiconductor 22 circuit in Figure 1 into a fourth semiconductor 28 circuit with the same function, and other circuit structures are all the same as Figure 1 is the same and will not be repeated.

As shown in Figure 5, it can be known from Figure 5 that the second semiconductor 22 is an N-channel metal oxide semiconductor field effect transistor, the fourth semiconductor 28 is a P channel metal oxide semiconductor field effect transistor, and the source S of the fourth semiconductor 28 is It is connected to the positive input terminal 15 of the voltage comparator 20 , the drain D of the fourth semiconductor 28 is connected to the negative power supply terminal of the voltage comparator 20 , and the gate G of the fourth semiconductor 28 is connected to the gate G of the first semiconductor 21 .

As shown in FIG. 5, it can be seen from the figure that when the drain of the third semiconductor 23 When the pole D and the source S are open, the drain D and the source S of the fourth semiconductor 28 are open, and when the drain D and the source S of the third semiconductor 23 are turned on, the drain D and the source of the fourth semiconductor 28 are open. S is turned on, and other action principles for protecting the DC power supply 14 when the load 10 is short-circuited are the same as those in FIG. 1 and will not be repeated here.

As shown in Figure 6, it is the sixth embodiment of the circuit protection device of the present invention. It can be seen from the figure that the circuit of the second semiconductor 22 and the third resistor 25 in Figure 1 are omitted, and the circuit of the first semiconductor 21 is omitted. The source S is connected to the first end of the resistance sensor (Resistor Sensor) 29 and the positive input end 15 of the voltage comparator 20, and the second end of the resistance sensor 29 is connected to the negative power supply end of the voltage comparator 20. Other circuit structures All are the same as those in Fig. 1 and will not be repeated.

As shown in Figure 6, it can be seen from Figure 6 that when the two ends of the load 10 are short-circuited, the drain current of the first semiconductor 21 rises, and when passing through the resistance sensor 29, the voltage at the first end of the resistance sensor 29 That is, the voltage of the positive input terminal 15 of the voltage comparator 20, when the voltage of the positive input terminal 15 of the voltage comparator 20 was higher than the reference voltage supplied by the third power supply 13 of the negative input terminal 16 of the voltage comparator 20, the voltage comparator The output terminal 17 of the device 20 outputs a positive voltage to supply power to the gate G of the third semiconductor 23, so that the drain D and the source S of the third semiconductor 23 are turned on. At this time, the drain D and the source of the first semiconductor 21 S is open circuit, so as to achieve the purpose of protecting the DC power supply 14 .

The second resistor 19, the third semiconductor 23 and the voltage comparator 20 have a self-locking function and the first semiconductor 21 has a self-protection function. The operating principles are the same as those in FIG. 1 and will not be repeated.

As shown in FIG. 7, it is the seventh embodiment of the circuit protection device of the present invention. It can be seen from the figure that it does not use the second power supply 12, the first resistor 18 and the first diode 24 in FIG. 1, and other circuits The structures are the same as those in FIG. 1 and will not be repeated.

As shown in Figure 7, when the first power supply 11 supplies power to the second resistor 19 To the gate G of the first semiconductor 21, the drain D and the source S of the first semiconductor 21 are turned on at this time.

When the output terminal 17 of the voltage comparator 20 outputs a positive voltage to supply power to the gate G of the third semiconductor 23, the drain D and the source S of the third semiconductor 23 are turned on, and the drain D and the source S of the first semiconductor 21 are connected simultaneously. The source S is open.

The second resistor 19, the third semiconductor 23 and the voltage comparator 20 have a self-locking function and the first semiconductor 21 has a self-protection function. The operating principles are the same as those in FIG. 1 and will not be repeated.

As can be seen from the above, the first power supply 11, the second power supply 12 and the third power supply 13 in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 and Fig. The diagrams are marked with dots for the sake of brevity. All knowledgeable people in the industry know that the power supply has a positive terminal and a negative terminal, which are not marked in the figure and are hereby specifically stated.

It can be known that the present invention can be implemented according to the description of the above-mentioned action principle and functional action.

10: load

11: The first power supply

12: Second power supply

13: The third power supply

14: DC power supply

15: The positive input terminal of the voltage comparator

16: Negative input terminal of voltage comparator

17: The output terminal of the voltage comparator

18: First resistor

19: Second resistor

20: Voltage comparator

21:First Semiconductor

22:Second semiconductor

23: The third semiconductor

24: The first diode

25: Third resistor

Claims (10)

A circuit protection device, comprising: A first semiconductor has a drain, a source and a gate, the drain of the first semiconductor is used to connect the second terminal of the load, the first terminal of the load is connected to the positive terminal of the DC power supply, the The source of the first semiconductor is used to connect the negative terminal of the DC power supply; A second semiconductor having a drain, a source and a gate, the drain of the second semiconductor is connected to the drain of the first semiconductor, the gate of the second semiconductor is connected to the gate of the first semiconductor; a third semiconductor having a drain, a source and a gate, the source of the third semiconductor is connected to the source of the second semiconductor; A first resistor has a first end and a second end, the second end of the first resistor is connected to the gate of the first semiconductor and the gate of the second semiconductor, the second end of the first resistor One end is used to provide the second power connection; A second resistor has a first end and a second end, the second end of the second resistor is connected to the drain of the third semiconductor, the first end of the second resistor is connected to the first power supply use; A third resistor has a first end and a second end, the first end of the third resistor is connected to the source of the second semiconductor and the source of the third semiconductor, the first end of the third resistor The two terminals are connected to the source of the first semiconductor; A first diode having an anode terminal and a cathode terminal, the anode terminal of the first diode is connected to the gate of the first semiconductor, the cathode terminal of the first diode is connected to the drain of the third semiconductor ;and A voltage comparator has a positive input terminal, a negative input terminal and an output terminal, the positive input terminal of the voltage comparator is connected to the source of the second semiconductor, the output terminal of the voltage comparator is connected to the source of the third semiconductor Gate, the negative input terminal of the voltage comparator provides a third power supply connection For the purpose, the third power supply is the reference voltage of the negative input terminal of the voltage comparator. A circuit protection device, comprising: A first semiconductor has a drain, a source and a gate, the drain of the first semiconductor is used to connect the second terminal of the load, the first terminal of the load is connected to the positive terminal of the DC power supply, the The source of the first semiconductor is used to connect the negative terminal of the DC power supply; A second semiconductor having a drain, a source and a gate, the drain of the second semiconductor is connected to the drain of the first semiconductor, the gate of the second semiconductor is connected to the gate of the first semiconductor; a third semiconductor having a drain, a source and a gate, the source of the third semiconductor is connected to the source of the second semiconductor; A second resistor has a first end and a second end, the second end of the second resistor is connected to the drain of the third semiconductor, the gate of the second semiconductor and the gate of the first semiconductor , the first end of the second resistor is used to provide the first power connection; A third resistor has a first end and a second end, the first end of the third resistor is connected to the source of the second semiconductor and the source of the third semiconductor, the first end of the third resistor two terminals connected to the source of the first semiconductor; and A voltage comparator has a positive input terminal, a negative input terminal and an output terminal, the positive input terminal of the voltage comparator is connected to the source of the second semiconductor, the output terminal of the voltage comparator is connected to the source of the third semiconductor Gate, the negative input terminal of the voltage comparator is used to provide a third power supply connection, and the third power supply is the reference voltage of the negative input terminal of the voltage comparator. The circuit protection device as described in item 1 or 2 of the scope of the patent application, wherein the first semiconductor, the second semiconductor and the third semiconductor are N-channel metal-oxide-semiconductor field-effect transistors, and any one of the semiconductors Both bodies can be replaced by insulated gate bipolar transistors. The circuit protection device as described in item 1 or 2 of the scope of the patent application, wherein the second semiconductor can be replaced by a fourth semiconductor, and the fourth semiconductor is a P-channel metal oxide semiconductor field effect transistor. The circuit protection device described in item 1 or 2 of the scope of the patent application further includes: The drain of the first semiconductor is connected to the first end of the first voltage dividing resistor; The source of the first semiconductor is connected to the second terminal of the second voltage dividing resistor; The drain of the second semiconductor is connected to the second end of the first voltage dividing resistor and the first end of the second voltage dividing resistor; and The source of the second semiconductor is connected to the positive input terminal of the voltage comparator. The circuit protection device described in item 1 or 2 of the scope of the patent application further includes: The source of the first semiconductor is connected to the first terminal of the resistance sensor and the positive input terminal of the voltage comparator; the second end of the resistive sensor is connected to the negative power supply end of the voltage comparator; and The function of the resistance sensor is to use the voltage drop generated by the drain current of the first semiconductor flowing through the resistance sensor as the input voltage of the positive input terminal of the voltage comparator. A self-locking circuit device, comprising: a second resistor having a first end and a second end, the first end of the second resistor providing the first power connection; a third semiconductor having a drain, a source and a gate, the drain of the third semiconductor being connected to the second end of the second resistor; and A voltage comparator having a positive input terminal, a negative input terminal and a Output terminal, the output terminal of the voltage comparator is connected to the gate of the third semiconductor, the positive input terminal of the voltage comparator is connected to the source of the third semiconductor, the positive input terminal of the voltage comparator is connected to the input voltage For use, the negative input terminal of the voltage comparator is used to provide a third power supply connection, and the third power supply is a reference voltage for the negative input terminal of the voltage comparator. The self-locking circuit device described in item 7 of the scope of the patent application, wherein the third semiconductor is an N-channel metal-oxide-semiconductor field-effect transistor, which can be replaced by an insulated gate bipolar transistor. The self-locking circuit device as described in item 7 of the scope of the patent application, wherein a third resistor is connected between the positive input terminal of the voltage comparator and the negative power supply terminal of the voltage comparator. The self-locking circuit device described in item 7 of the scope of the patent application, wherein the positive power terminal of the voltage comparator is connected to the positive power terminal of the first power supply, and the negative power supply terminal of the voltage comparator is connected to the negative power terminal of the first power supply .

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