TWI413326B - Power protection circuit - Google Patents

Abstract

The present invention relates to a power protection circuit including a power providing unit, a first voltage converter, a second voltage converter, a first switch, a second switch, a first voltage detecting circuit, a second voltage detecting circuit, a first alarming circuit, and a second alarming circuit. The first and second switches are respectively connected to the power providing unit and the first voltage converters, or the power providing unit and the first and second voltage converters. The first and second voltage detecting circuits are respectively connected to the first and second voltage converters. The first and second alarming circuits are respectively connected to the first and second voltage detecting circuits. When the input voltage of the first or the second voltage detecting circuit becomes lower, the first switch cuts off the first voltage converter and actuates the first alarming circuit alarming, or the second switch cuts off the second voltage converter and actuates the second alarming circuit alarming.

Description

Power protection circuit

The invention relates to a power protection circuit.

The board sometimes has a load failure. When the load fails, the output current tends to increase or even short. Since the alarm and protection device are not set, when a fault occurs, on the one hand, it may cause electric shock or other accidents, and it is unsafe. On the other hand, it is impossible to know the faulty component or line. In order to check and eliminate the fault, it is often necessary to cut off the main fault. The entire power supply system of the machine checks the entire board and is time consuming and labor intensive.

In view of this, it is necessary to provide a power protection circuit that can issue an alarm protection signal when an abnormality occurs in the load.

A power protection circuit includes a power supply unit, a first voltage converter, a second voltage converter, a first switching circuit, and a second switching circuit. The first switch circuit is connected between the power supply unit and the first voltage converter. The second switch circuit is connected between the power supply unit and the second voltage converter. The power supply unit is configured to provide a voltage source for the first and second voltage converters. The power protection circuit further includes a first voltage detecting circuit, a second voltage detecting circuit, a first alarm circuit and a second alarm circuit. The first voltage detecting circuit is connected to the first voltage converter. The second electricity A voltage detection circuit is coupled to the second voltage converter. The first alarm circuit is connected to the first voltage detecting circuit. The second alarm circuit is connected to the second voltage detecting circuit. When the input voltage of the first voltage detecting circuit decreases, the first switching circuit cuts off the first voltage converter, and the power supply unit drives the first alarm circuit to send an alarm signal. When the input voltage of the second voltage detecting circuit decreases, the second switching circuit cuts off the second voltage converter, and the power supply unit drives the second alarm circuit to send an alarm signal.

Compared with the prior art, when the first voltage detecting circuit detects that a fault occurs in the first voltage converter, the first switching circuit cuts off the first voltage converter and simultaneously drives the first alarm circuit. A corresponding alarm signal is sent to remind the person that the first voltage converter is faulty. When the second voltage detecting circuit detects that a fault occurs in the second voltage converter, the second switching circuit cuts off the second voltage converter, and simultaneously drives the second alarm circuit to issue a corresponding alarm signal. Remind the person that the second voltage converter is faulty. In this way, the cause of the fault can be detected in a timely and effective manner and various accidents that may occur are avoided.

100‧‧‧Power protection circuit

10‧‧‧Power supply unit

21‧‧‧First voltage converter

22‧‧‧Second voltage converter

211, 221‧‧‧ input

212, 222‧‧‧ output

31‧‧‧First switch circuit

32‧‧‧Second switch circuit

Q1‧‧‧First transistor

Q2‧‧‧Second transistor

D‧‧‧Drain

S‧‧‧ source

G‧‧‧Gate

C1, C2‧‧‧ time delay capacitor

41‧‧‧First voltage detection circuit

42‧‧‧Second voltage detection circuit

Q3‧‧‧ Third transistor

Q4‧‧‧4th transistor

R1-R24‧‧‧ resistance

B‧‧‧ base

C‧‧‧ Collector

E‧‧‧ emitter

Q5‧‧‧ fifth transistor

Q6‧‧‧ sixth transistor

51‧‧‧First alarm circuit

52‧‧‧Second alarm circuit

Q7‧‧‧ seventh transistor

Q8‧‧‧ eighth transistor

Q9‧‧‧Ninth transistor

D1‧‧‧First Light Emitting Diode

Q10‧‧‧10th transistor

Q11‧‧‧Eleventh transistor

Q12‧‧‧12th transistor

D2‧‧‧Second light-emitting diode

1 is a functional block diagram of a power protection circuit according to an embodiment of the present invention; and FIG. 2 is a circuit diagram of the power protection circuit of FIG.

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , the power protection circuit 100 of the present invention includes a power supply unit 10 , a first voltage converter 21 , a second voltage converter 22 , a first switch circuit 31 , and a second switch circuit . 32. A first voltage detecting circuit 41 and a second The voltage detecting circuit 42 , a first alarm circuit 51 and a second alarm circuit 52 . The power supply unit 10 is configured to provide a voltage source for the first voltage converter 21 and the second voltage converter 22. The first switch circuit 31 is connected between the power supply unit 10 and the first voltage converter 21. The second switch circuit 32 is connected between the power supply unit 10 and the second voltage converter 22. The first voltage detecting circuit 41 is connected to the first voltage converter 21 for detecting whether the first voltage converter 21 has a fault. The second voltage detecting circuit 42 is connected to the second voltage converter 22 for detecting whether the second voltage converter 22 has a fault. The first alarm circuit 51 is connected to the first voltage detecting circuit 41. The second alarm circuit 52 is connected to the second voltage detecting circuit 42. When the first voltage detecting circuit 41 detects that a fault occurs in the first voltage converter 21, the first switching circuit 31 cuts off the first voltage converter 21 while the power supply unit 10 drives The first alarm circuit 51 sends a corresponding alarm signal. When the second voltage detecting circuit 42 detects that a fault occurs in the second voltage converter 22, the second switching circuit 32 cuts off the second voltage converter 22 while the power supply unit 10 drives The second alarm circuit 52 sends a corresponding alarm signal.

It can be understood that, in addition to the present embodiment, three or more voltage converters, switching circuits, voltage detecting circuits, and alarm circuits may be separately provided according to the above principles, and are not limited to the embodiment.

Referring to FIG. 2, in the embodiment, the power supply unit 10 is configured to output a voltage of 12V, and the first voltage converter 21 is configured to convert a voltage of 12V output by the power supply unit 10 into 5V. The second voltage converter 22 is configured to convert the 12V voltage output by the power supply unit 10 to 3.3V. The first voltage converter 21 The output 212 is coupled to a load (not shown). The output 222 of the second voltage converter 22 is coupled to another load (not shown).

The first switch circuit 31 is a first transistor Q1, and the second switch circuit 32 is a second transistor Q2. In this embodiment, the first transistor Q1 and the second transistor Q2 are both P-MOS transistors, and the drain D of the first transistor Q1 is connected to the input terminal 211 of the first voltage converter 21, The gate G of the first transistor Q1 is connected to the voltage detecting circuit 40 and connected to the ground via a delay capacitor C1. The source S of the first transistor Q1 is connected to the power supply unit 10. The drain D of the second transistor Q2 is connected to the input terminal 221 of the second voltage converter 22, and the gate G of the second transistor Q2 is connected to the voltage detecting circuit 40 and passes through a delay capacitor C2. Connect to the ground. The source S of the second transistor Q2 is connected to the power supply unit 10. At the same time, the gate G of the second transistor Q2 is connected to the voltage detecting circuit 40.

The first voltage detecting circuit 41 includes a third transistor Q3 and a fourth transistor Q4. In this embodiment, the third transistor Q3 and the fourth transistor Q4 are both NPN type transistors. The collector C of the third transistor Q3 is connected to the gate G of the first transistor Q1 via a resistor R2. The emitter E of the third transistor Q3 is connected to the ground by a resistor R1. The base B of the third transistor Q3 is connected to the output terminal 212 of the first voltage converter 21 via a resistor R3. The collector C of the fourth transistor Q4 is connected to the power supply unit 10 by a resistor R4. The emitter E of the fourth transistor Q4 is grounded via a resistor R5. The base B of the fourth transistor Q4 is connected to the power supply unit 10 by two resistors R6, R7. A resistor R8 is connected in series between the collector C of the third transistor Q3 and the collector C of the fourth transistor Q4. A resistor R9 is connected in series between the resistor R6 and the ground.

The second voltage detecting circuit 42 includes a fifth transistor Q5 and a sixth transistor Q6. In the present embodiment, the fifth transistor Q5 and the sixth transistor Q6 are both NPN type transistors. The collector C of the fifth transistor Q5 is connected to the gate G of the second transistor Q2 by a resistor R10. The emitter E of the fifth transistor Q5 is connected to the ground by a voltage dividing resistor R11. The base B of the fifth transistor Q5 is connected to the output terminal 222 of the second voltage converter 22 by a resistor R12. The collector C of the sixth transistor Q6 is connected to the power supply unit 10 by a resistor R13. The emitter E of the sixth transistor Q6 is grounded via a resistor R14. The base B of the sixth transistor Q6 is connected to the power supply unit 10 by two resistors R15, R16. A resistor R17 is connected in series between the collector C of the fifth transistor Q5 and the collector C of the sixth transistor Q6. A resistor R18 is connected in series between the resistor R15 and the ground.

The first alarm circuit 51 includes a seventh transistor Q7, an eighth transistor Q8, a ninth transistor Q9, and a first LED diode D1. In this embodiment, the seventh transistor Q7 is an NPN type transistor. The eighth transistor Q8 and the ninth transistor Q9 are both N-MOS transistors. The base B of the seventh transistor Q7 is connected to the collector C of the third transistor Q3, and the collector C of the seventh transistor Q7 is connected to the power supply unit 10 by a resistor R19, and the seventh transistor Q7 The emitter E is connected to the collector C of the fourth transistor Q4 by a resistor R20. The gates G of the eighth transistor Q8 and the ninth transistor Q9 are both connected to the collector C of the fourth transistor Q4. The source S of the eighth transistor Q8 is connected to the drain D of the ninth transistor Q9. The source S of the ninth transistor Q9 is grounded. The drain D of the eighth transistor Q8 is connected to the cathode of the first LED D1. The anode of the first LED D1 is connected to the power supply unit 10 by a resistor R21.

The second alarm circuit 52 includes a tenth transistor Q10, an eleventh transistor Q11, a twelfth transistor Q12, and a second LED Dipole D2. In this embodiment, the tenth transistor Q10 is an NPN type transistor. The eleventh transistor Q11 and the twelfth transistor Q12 are both N-MOS electrowinning tubes. The base B of the tenth transistor Q10 is connected to the collector C of the fifth transistor Q5, and the collector C of the tenth transistor Q10 is connected to the power supply unit 10 by a resistor R22, and the tenth transistor Q10 The emitter E is connected to the collector C of the sixth transistor Q6 via a resistor R23. The gates G of the eleventh transistor Q11 and the twelfth transistor Q12 are both connected between the source S of the eighth transistor Q8 and the drain D of the ninth transistor Q9. The source S of the eleventh transistor Q11 is connected to the drain D of the twelfth transistor Q12. The source S of the twelfth transistor Q12 is grounded. The drain D of the eleventh transistor Q11 is connected to the cathode of the second LED D2. The anode of the second LED D2 is connected to the power supply unit 10 by a resistor R24.

In use, when the load fails to cause the first voltage converter 21 to have an abnormal output, the base B voltage of the third transistor Q3 of the first voltage detecting circuit 41 is lowered. That is, the input voltage of the first voltage detecting circuit 41 is lowered. The third transistor Q3 is turned off, the voltage of the gate G of the first transistor Q1 is increased, the first transistor Q1 is turned off, the input terminal 211 of the first voltage converter 21 stops inputting, and the first voltage is converted. The device 21 stops working. At the same time, the seventh transistor Q7, the eighth transistor Q8, and the ninth transistor Q9 are both turned on, and the first light-emitting diode D1 emits light, thereby issuing an alarm. And since the gates G of the eleventh transistor Q11 and the twelfth transistor Q12 are both connected between the source S of the eighth transistor Q8 and the drain D of the ninth transistor Q9, The source S of the ninth transistor Q9 is grounded, and therefore, the eleventh transistor The gate G of the body Q11 and the gate G of the twelfth transistor Q12 obtain a low level, and the eleventh transistor Q11 and the twelfth transistor Q12 are both turned off, and the second light emitting diode D2 Does not shine.

When the load is faulty, causing the second voltage converter 22 to have an abnormal output, the base B voltage of the fifth transistor Q5 of the second voltage detecting circuit 42 is lowered, that is, the first The input voltage of the two voltage detecting circuit 42 is lowered. The fifth transistor Q5 is turned off, the voltage of the gate G of the second transistor Q2 is increased, and the second transistor Q2 is turned off. At the same time, the sixth transistor Q6, the tenth transistor Q10, the eleventh transistor Q11, and the twelfth transistor Q12 are both turned on, and the second light-emitting diode D2 emits light, thereby issuing an alarm. And since the gates G of the eighth transistor Q8 and the ninth transistor Q9 are both connected between the source S of the eleventh transistor Q11 and the drain D of the twelfth transistor Q12, The source S of the twelfth transistor Q12 is grounded. Therefore, the gate G of the eighth transistor Q8 and the gate G of the ninth transistor Q9 get a low level, and the eighth transistor Q8 and the Nine transistors Q9 are all turned off, and the first light-emitting diode D1 does not emit light.

When the first voltage detecting circuit detects that a fault occurs in the first voltage converter, the first switching circuit cuts off the first voltage converter, and simultaneously drives the first alarm circuit to issue a corresponding alarm signal. Remind the person that the first voltage converter is faulty. When the second voltage detecting circuit detects that a fault occurs in the second voltage converter, the second switching circuit cuts off the second voltage converter, and simultaneously drives the second alarm circuit to issue a corresponding alarm signal. Remind the person that the second voltage converter is faulty. In this way, the cause of the fault can be detected in a timely and effective manner and various accidents that may occur are avoided.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. please. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100‧‧‧Power protection circuit

10‧‧‧Power supply unit

21‧‧‧First voltage converter

22‧‧‧Second voltage converter

211, 221‧‧‧ input

212, 222‧‧‧ output

31‧‧‧First switch circuit

32‧‧‧Second switch circuit

Q1‧‧‧First transistor

Q2‧‧‧Second transistor

D‧‧‧Drain

S‧‧‧ source

G‧‧‧Gate

C1, C2‧‧‧ time delay capacitor

41‧‧‧First voltage detection circuit

42‧‧‧Second voltage detection circuit

Q3‧‧‧ Third transistor

Q4‧‧‧4th transistor

R1-R24‧‧‧ resistance

B‧‧‧ base

C‧‧‧ Collector

E‧‧‧ emitter

Q5‧‧‧ fifth transistor

Q6‧‧‧ sixth transistor

51‧‧‧First alarm circuit

52‧‧‧Second alarm circuit

Q7‧‧‧ seventh transistor

Q8‧‧‧ eighth transistor

Q9‧‧‧Ninth transistor

D1‧‧‧First Light Emitting Diode

Q10‧‧‧10th transistor

Q11‧‧‧Eleventh transistor

Q12‧‧‧12th transistor

D2‧‧‧Second light-emitting diode

Claims (9)

A power protection circuit includes a power supply unit, a first voltage converter, a second voltage converter, a first switch circuit, and a second switch circuit, wherein the first switch circuit is connected to the power supply Between the unit and the first voltage converter, the second switch circuit is connected between the power supply unit and the second voltage converter, and the power supply unit is configured to be the first The second voltage converter provides a voltage source, and the improvement is that the power protection circuit further includes a first voltage detecting circuit, a second voltage detecting circuit, a first alarm circuit and a second alarm circuit, a voltage detecting circuit is connected to the first voltage converter, the second voltage detecting circuit is connected to the second voltage converter, and the first alarm circuit is connected to the first voltage detecting circuit. The second alarm circuit is connected to the second voltage detecting circuit, when the input voltage of the first voltage detecting circuit is lowered, the first switching circuit cuts off the first voltage converter, and the same The power supply unit drives the first alarm circuit to send an alarm signal, and when the input voltage of the second voltage detection circuit decreases, the second switch circuit cuts off the second voltage converter, and the power supply The unit drives the second alarm circuit to send an alarm signal. The power protection circuit of claim 1, wherein: the first switch circuit comprises a first transistor, and the second switch circuit comprises a second transistor, when the first voltage is detected. When the input voltage of the circuit decreases, the first transistor cuts off the first voltage converter, and when the input voltage of the second voltage detecting circuit decreases, the second transistor cuts off the second Voltage converter. The power protection circuit of claim 2, wherein: the output of the first voltage converter is connected to a load, and the output of the second voltage converter is connected to another load, the a transistor and a second transistor are both P-MOS transistors, a drain of the first transistor is connected to an input end of the first voltage converter, and a gate of the first transistor is connected to the first a voltage detecting circuit, a source of the first transistor is connected to the power supply unit, a source of the second transistor is connected to the power supply unit, and a drain of the second transistor is connected to An input end of the second voltage converter, a gate of the second transistor is connected to the second voltage detecting circuit. The power protection circuit of claim 3, wherein: the first voltage detecting circuit comprises a third transistor and a fourth transistor, and the third transistor and the fourth transistor are both An NPN type transistor, a collector of the third transistor is connected to a gate of the first transistor by a resistor, an emitter of the third transistor is connected to a ground, and the third transistor is a base is connected to an output end of the first voltage converter, a collector of the fourth transistor is connected to the power supply unit, an emitter of the fourth transistor is grounded, and the fourth transistor is The base is connected to the power supply unit, and the collector of the third transistor and the collector of the fourth transistor are connected to each other. The power protection circuit of claim 3, wherein: the second voltage detecting circuit comprises a fifth transistor and a sixth transistor, and the fifth transistor and the sixth transistor are both An NPN type transistor, a collector of the fifth transistor is connected to a gate of the second transistor by a resistor, an emitter of the fifth transistor is connected to a ground, and the fifth transistor is a base is connected to an output end of the second voltage converter, and a collector of the sixth transistor is connected to the power supply unit The emitter of the sixth transistor is grounded, the base of the sixth transistor is connected to the power supply unit, and the collector of the fifth transistor and the collector of the sixth transistor are connected to each other. The power protection circuit of claim 4, wherein: the first alarm circuit comprises a seventh transistor, an eighth transistor, a ninth transistor, and a first LED, The seventh transistor is an NPN type transistor, and the eighth transistor and the ninth transistor are both N-MOS transistors, and the base of the seventh transistor is connected to the collector of the third transistor, and the seventh a collector of the transistor to the power supply unit, an emitter of the seventh transistor is connected to a collector of the fourth transistor, and a gate of the eighth transistor and the ninth transistor are connected to a fourth a collector of the transistor, a source of the eighth transistor is connected to a drain of the ninth transistor, a source of the ninth transistor is grounded, and a drain of the eighth transistor is connected to the first a cathode of the light emitting diode, wherein an anode of the first light emitting diode is connected to the power supply unit by a resistor. The power protection circuit of claim 5, wherein the second alarm circuit comprises a tenth transistor, an eleventh transistor, a twelfth transistor, and a second LED. The tenth transistor is an NPN type transistor, and the eleventh transistor and the twelfth transistor are both N-MOS transistors, and the base of the tenth transistor is connected to the fifth transistor. An electrode, a collector of the tenth transistor, to the power supply unit, an emitter of the tenth transistor is connected to a collector of the sixth transistor, and a gate of the eleventh transistor and the twelfth transistor a pole is connected between a source of the eighth transistor and a drain of the ninth transistor, and a source of the eleventh transistor is connected to a drain of the twelfth transistor, a source of twelve transistors is grounded, and a drain of the eleventh transistor is connected to a cathode of the second light emitting diode The anode of the second light emitting diode is connected to the power supply unit by a resistor. The power protection circuit of claim 3, wherein the first transistor is grounded by a delay capacitor. The power protection circuit of claim 3, wherein: the second transistor is grounded by a delay capacitor.