CN104426125B - A kind of overvoltage crowbar and the lamps and lanterns with over-voltage protecting function - Google Patents

A kind of overvoltage crowbar and the lamps and lanterns with over-voltage protecting function Download PDF

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Publication number
CN104426125B
CN104426125B CN201310373533.XA CN201310373533A CN104426125B CN 104426125 B CN104426125 B CN 104426125B CN 201310373533 A CN201310373533 A CN 201310373533A CN 104426125 B CN104426125 B CN 104426125B
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circuit
output end
reference voltage
connected
end
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CN201310373533.XA
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Chinese (zh)
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CN104426125A (en
Inventor
周明杰
杨小军
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深圳市海洋王照明工程有限公司
海洋王照明科技股份有限公司
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Priority to CN201310373533.XA priority Critical patent/CN104426125B/en
Publication of CN104426125A publication Critical patent/CN104426125A/en
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Abstract

The embodiment of the invention discloses a kind of overvoltage crowbar and with the lamps and lanterns of over-voltage protecting function; overvoltage crowbar includes: reference voltage generating circuit; reference voltage generating circuit; comparison circuit and protection circuit; wherein: the input terminal of reference voltage generating circuit is connected to the output end of reference voltage generating circuit, and the reference voltage that reference voltage generating circuit is generated exports after amplifying a preset multiple from its output end;The output voltage for the circuit that the overvoltage crowbar is protected and the reference voltage are compared by comparison circuit, the output end output over-voltage protection signal when output voltage is greater than the reference voltage;When protecting the driving termination of circuit to receive the overvoltage protection signal, the first output end and second output terminal disconnect disconnecting the connection between output voltage and load.Overvoltage crowbar provided by the invention and lamps and lanterns with over-voltage protecting function, with the simple and at low cost beneficial effect of circuit.

Description

A kind of overvoltage crowbar and the lamps and lanterns with over-voltage protecting function

Technical field

The present invention relates to electronic circuit fields, and in particular to a kind of overvoltage crowbar and the lamp with over-voltage protecting function Tool.

Background technique

Traditional overvoltage crowbar is to compare sampled voltage and outside by comparator by sampling circuit samples voltage value The size of reference voltage, and corresponding electric signal trigger protection is exported when sampled voltage is greater than reference voltage (over-voltage occur) Circuit operation.Traditional overvoltage crowbar needs to introduce sample circuit and external reference voltage source, and circuit is complicated, circuit cost It is high.

Summary of the invention

The embodiment of the invention provides a kind of overvoltage crowbar and with the lamps and lanterns of over-voltage protecting function, circuit it is simple and It is at low cost.

The application first aspect provides a kind of overvoltage crowbar, comprising: reference voltage generating circuit, reference voltage generate Circuit, comparison circuit and protection circuit, in which:

The input terminal of the reference voltage generating circuit is connected to the voltage output end of front stage circuits, and the reference voltage is raw A constant reference voltage is exported at the output end of circuit;

The input terminal of the reference voltage generating circuit is connected to the output end of the reference voltage generating circuit, the ginseng Examining voltage generation circuit will export after the reference voltage one preset multiple of amplification from its output end;

The first input end of the comparison circuit is connected to the voltage output end, the second input terminal of the comparison circuit It is connected to the output end of the reference voltage generating circuit, when the output voltage of the voltage output end is greater than the reference voltage When the output voltage of generative circuit, the output end output over-voltage protection signal of the comparison circuit;

The driving end of the protection circuit is connected to the output end of the comparison circuit, the first output of the protection circuit On the circuit that end and second output terminal are connected on the voltage output end and load is constituted, when the driving termination of the protection circuit The first output end of the protection circuit and second output terminal when the overvoltage protection signal is received to disconnect, otherwise, the protection First output end of circuit is connected to second output terminal.

Optionally, the reference voltage generating circuit includes one or three end adjustable shunt reference sources, in which:

The input terminal of the just extremely described reference voltage generating circuit of three end adjustable shunt reference source is connected to described Voltage output end, the cathode of three end adjustable shunt reference source are connected to grounding point, three end adjustable shunt reference source Reference end is that the output end of the reference voltage generating circuit is connected to the input terminal of the reference voltage generating circuit.

Optionally, the reference voltage generating circuit includes first resistor, second resistance and the first integrated operational amplifier, Wherein,

The homophase input pin of first integrated operational amplifier is that the input terminal of the reference voltage generating circuit connects It is connected to the output end of the reference voltage generating circuit, the reversed input pin of first integrated operational amplifier is connected to institute The first end of first resistor is stated, the first end of the first resistor is connected to the first end of the second resistance, second electricity The second end of resistance is connected to the output pin of first integrated operational amplifier, the output of first integrated operational amplifier Pin is the output end of the reference voltage generating circuit, and the power pins of first integrated operational amplifier are connected to power supply The grounding pin of power supply, the second end of the first resistor and first integrated operational amplifier is connected to grounding point.

Optionally, the comparison circuit includes the second integrated operational amplifier, wherein

The homophase input pin of second integrated operational amplifier is that the first input end of the comparison circuit is connected to The voltage output end, the reversed input pin of second integrated operational amplifier are the second input terminal of the comparison circuit It is connected to the output end of the reference voltage generating circuit, the output pin of second integrated operational amplifier is the comparison The output end of circuit is connected to the driving end of the protection circuit, and the power pins of second integrated operational amplifier are connected to The grounding pin of power supply, second integrated operational amplifier is connected to ground terminal.

Optionally, the protection circuit includes triode and photoelectrical coupler,

The base stage of the triode is that the driving end of the protection circuit is connected to the output end of the comparison circuit, described The collector of triode is connected to the anode of the voltage output end and the photoelectrical coupler, the cathode of the photoelectrical coupler It is connected to grounding point, the collector and emitter of the photoelectrical coupler is respectively the first output end and the of the protection circuit Two output ends are connected on the circuit of the voltage output end and the load composition.

Optionally, the reference voltage generating circuit further includes 3rd resistor, wherein

The 3rd resistor is connected between the voltage output end and the anode of three end adjustable shunt reference source.

Optionally, the reference voltage generating circuit further includes the 4th resistance, wherein

4th resistance is connected on the homophase input pin and the reference voltage of first integrated operational amplifier Between the output end of generative circuit.

Optionally, the protection circuit further includes the 5th resistance and the 6th resistance, wherein

5th resistance is connected between the voltage output end and the collector of the triode, the 6th resistance It is connected on the circuit that the voltage output end, the first output end of the load and the protection circuit and second output terminal are constituted On.

The application second aspect provides a kind of lamps and lanterns with over-voltage protecting function, including DC power supply, light source and such as sheet Apply for overvoltage crowbar described in any implementation of first aspect or first aspect, wherein

The voltage output end of the DC power supply is connected to the reference voltage generating circuit in the overvoltage crowbar Input terminal, the first output end and second output terminal of the protection circuit in the overvoltage crowbar are connected in series in the direct current On the circuit that the voltage output end of power supply and the light source are constituted.

Overvoltage crowbar provided by the invention generates a constant reference voltage, ginseng by reference voltage generating circuit The reference voltage that output size after the reference circuit one preset multiple of amplification is equal to HVT high voltage threshold by voltage generation circuit is examined, The output voltage of the claimed circuit of overvoltage crowbar is compared with the reference voltage by comparing circuit, and is being exported Output over-voltage protection signal control protection electric circuit disconnects the claimed electricity of overvoltage crowbar when voltage is greater than the HVT high voltage threshold The circuit that the voltage output end on road and load are constituted, to avoid output end over-voltage damage caused by load.The present invention passes through Reference voltage is amplified to HVT high voltage threshold by reference voltage generating circuit, and output voltage is directly compared with the HVT high voltage threshold, nothing Sample circuit and external reference voltage source need to be introduced, circuit is simple, and circuit cost is low.

Detailed description of the invention

In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with It obtains other drawings based on these drawings.

Fig. 1 is a kind of circuit diagram of overvoltage crowbar provided in an embodiment of the present invention;

Fig. 2 is the circuit diagram of another overvoltage crowbar provided in an embodiment of the present invention;

Fig. 3 is a kind of circuit diagram of lamps and lanterns with over-voltage protecting function provided in an embodiment of the present invention.

Specific embodiment

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other Embodiment shall fall within the protection scope of the present invention.

Referring to FIG. 1, Fig. 1 is a kind of circuit diagram of overvoltage crowbar provided in an embodiment of the present invention, comprising:

Reference voltage generating circuit 101, reference voltage generating circuit 102, comparison circuit 103 and protection circuit 104, In:

The input terminal of reference voltage generating circuit 101 is connected to the voltage output end V of front stage circuitsout, the reference voltage The output end of generative circuit exports a constant reference voltage;

The input terminal of reference voltage generating circuit 102 is connected to the output end of reference voltage generating circuit 101, reference voltage Generative circuit will export after reference voltage one preset multiple of amplification from its output end;

The first input end of comparison circuit 103 is connected to voltage output end Vout, the second input terminal of comparison circuit is connected to The output end of reference voltage generating circuit 102, when the output voltage of voltage output end is greater than the output of reference voltage generating circuit When voltage, the output end output over-voltage protection signal of comparison circuit;

The driving end of protection circuit 104 is connected to the output end of comparison circuit 103, protects the first output end of circuit 104 It is connected on second output terminal on the circuit of voltage output end and load composition, when the driving termination of protection circuit 104 received The first output end of protection circuit 104 and second output terminal disconnect when pressure protection signal, and otherwise, the first of protection circuit 104 is defeated Outlet is connected to second output terminal.

Wherein, above-mentioned preset multiple is set according to the HVT high voltage threshold of output voltage, for example, the rated value of output voltage is 10V, HVT high voltage threshold 15V, i.e. output voltage are more than that 15V is then over-voltage, and the reference voltage of reference voltage generating circuit output is 2.5V, then preset digit is set as 6.

Optionally, reference voltage generating circuit 101 may include one or three end adjustable shunt reference source (Adjustable Precision Shunt Regulators) U1, in which:

The anode of three end adjustable shunt reference source U1 is that the input terminal of benchmark voltage generation circuit 101 is connected to voltage output Hold Vout, the cathode of three end adjustable shunt reference source U1 is connected to grounding point, and the reference end of three end adjustable shunt reference source U1 is base The output end of quasi- voltage generation circuit 101 is connected to the input terminal of reference voltage generating circuit 102.

Optionally, reference voltage generating circuit 102 includes that first resistor R1, second resistance R2 and the first integrated computation amplify Device U2, wherein

The power pins of first integrated operational amplifier U2 are connected to power supply, and the first integrated operational amplifier U2's connects Ground pin is connected to ground terminal, and the homophase input pin of the first integrated operational amplifier U2 is reference voltage generating circuit 102 Input terminal is connected to the output end of reference voltage generating circuit 101, and the reversed input pin of the first integrated operational amplifier U2 connects It is connected to the first end of first resistor R2, the second end of first resistor R1 is connected to grounding point, the first end connection of first resistor R1 To the first end of second resistance R2, the second end of second resistance R2 is connected to the output end of the first integrated operational amplifier U2, the The output end of one integrated operational amplifier U2 is the output end of reference voltage generating circuit 102.

Optionally, comparison circuit 103 includes the second integrated operational amplifier U3, wherein

The non-inverting input terminal of second integrated operational amplifier U3 is that be connected to voltage defeated for the first input end of comparison circuit 103 Outlet, the inverting input terminal of the second integrated operational amplifier U3 are that the second input terminal of comparison circuit 103 is connected to the reference The output end of voltage generation circuit 102, the power pins of the second integrated operational amplifier U3 are connected to power supply, and second is integrated The grounding pin of operational amplifier U3 is connected to ground terminal,

Optionally, protection circuit 104 includes triode Q1 and photoelectrical coupler U4,

The base stage of triode Q1 is the output end for protecting the driving end of circuit 104 to be connected to comparison circuit 103, triode Q1 Collector be connected to the anode of voltage output end and photoelectrical coupler U4, the cathode of photoelectrical coupler U4 is connected to grounding point, The collector and emitter of photoelectrical coupler U4 is respectively the first output end and second output terminal for protecting circuit 104, is connected on On the circuit that voltage output end and load are constituted.

Wherein, it is three end adjustable shunt reference sources, the reference of TL431 that three end adjustable shunt reference source U1, which can be TL431, End can provide the reference voltage of 2.5V.

Wherein, the first integrated operational amplifier U2 in reference voltage generating circuit 102, can be LM324, wherein U2, R1, R2, composition amplifying circuit generate reference voltage, the reference voltage of output after reference voltage is amplified a preset multiple Are as follows: U1A=(1+R2/R5) × 2.5V, Q1 are triode, and U3 can be PC817.When output voltage is in normal voltage range When, photoelectrical coupler U4 work, by Vout, load, U4 composition circuit conducting, load normal power supply;Occur when output voltage When over-voltage, VoutOn voltage be greater than U2 output reference voltage, U3 output HIGH voltage, triode Q1 start to work, by the sun of U4 Pole pipe foot drags down, and U4 stops working at this time, Vout, load, U4 composition circuit open circuit, overvoltage protection is played the role of with this, Increase the service life of circuit.

Optionally, as shown in Fig. 2, reference voltage generating circuit can also include 3rd resistor R3, wherein

3rd resistor R3 is connected between voltage output end and the anode of three end adjustable shunt reference source U1.

Reference voltage generating circuit 102 can also include the 4th resistance R4, wherein

4th resistance R4 is connected on the homophase input pin and reference voltage generating circuit of the first integrated operational amplifier U2 Between 101 output end.

Protecting circuit 104 further includes the 5th resistance R5 and the 6th resistance R6, wherein

5th resistance R5 is connected between voltage output end and the collector of triode Q1, and the 6th resistance R6 is connected on voltage On the circuit that output end, the first output end of load and protection circuit 104 and second output terminal are constituted.

Wherein, R3, R4, R5, R6 are current-limiting resistance, play metering function.

Overvoltage crowbar provided in this embodiment generates a constant reference voltage by reference voltage generating circuit, Reference voltage generating circuit exports HVT high voltage threshold after the reference circuit is amplified a preset multiple, the overvoltage crowbar institute The output voltage of the circuit of protection is compared with the HVT high voltage threshold by comparing circuit, and is greater than the high pressure threshold in output voltage When value output over-voltage protection signal control protection electric circuit disconnect the voltage output end of the circuit that the overvoltage crowbar is protected with The circuit constituted is loaded, to avoid output end over-voltage damage caused by load.The present invention is by reference to voltage generation circuit Reference voltage is amplified to HVT high voltage threshold, output voltage is directly compared with the HVT high voltage threshold, without introduce sample circuit and External reference voltage source, circuit is simple, and circuit cost is low.

Referring to FIG. 3, Fig. 3 is a kind of lamps and lanterns with over-voltage protecting function provided in an embodiment of the present invention, comprising: direct current Overvoltage crowbar 203 in power supply 201, light source 203 and such as Fig. 1 or Fig. 2 embodiment in any possible implementation, In,

The voltage output end V of DC power supply 201outIt is connected to the defeated of the reference voltage generating circuit in overvoltage crowbar Enter to hold, the first output end of 203 protection circuit and second output terminal are connected in series in DC power supply 201 in overvoltage crowbar Voltage output end VoutOn the circuit constituted with light source 203.

Wherein, DC power supply 201 can be Switching Power Supply or linear power supply etc., and light source 203 can be LED light.

Lamps and lanterns provided in this embodiment with over-voltage protecting function are constant by reference voltage generating circuit generation one Reference voltage, reference voltage generating circuit by the reference circuit amplify a preset multiple after output size be equal to high pressure threshold The reference voltage of value, the output voltage of DC power supply is compared with the reference by comparing circuit, and is greater than in output voltage The circuit that output over-voltage protection signal control protection electric circuit disconnects DC power supply when the HVT high voltage threshold and load is constituted, to avoid Output end over-voltage is damaged caused by load.Reference voltage is amplified to high pressure threshold by reference to voltage generation circuit by the present invention Value, output voltage are directly compared with the HVT high voltage threshold, without introducing sample circuit and external reference voltage source, circuit letter Single, circuit cost is low.

The above disclosure is only the preferred embodiments of the present invention, cannot limit the right model of the present invention with this certainly It encloses, therefore equivalent changes made in accordance with the claims of the present invention, is still within the scope of the present invention.

Claims (7)

1. a kind of overvoltage crowbar characterized by comprising reference voltage generating circuit, reference voltage generating circuit compare Circuit and protection circuit, in which:
The input terminal of the reference voltage generating circuit is connected to the voltage output end of front stage circuits, and the reference voltage generates electricity The output end on road exports a constant reference voltage;
The reference voltage generating circuit includes one or three end adjustable shunt reference sources, in which:
The input terminal of the just extremely described reference voltage generating circuit of three end adjustable shunt reference source is connected to the voltage Output end, the cathode of three end adjustable shunt reference source are connected to grounding point, the reference of three end adjustable shunt reference source End is that the output end of the reference voltage generating circuit is connected to the input terminal of the reference voltage generating circuit;
The input terminal of the reference voltage generating circuit is connected to the output end of the reference voltage generating circuit, described with reference to electricity Press generative circuit that will export after the reference voltage one preset multiple of amplification from its output end;
The first input end of the comparison circuit is connected to the voltage output end, the second input terminal connection of the comparison circuit To the output end of the reference voltage generating circuit, when the output voltage of the voltage output end is generated greater than the reference voltage When the output voltage of circuit, the output end output over-voltage protection signal of the comparison circuit;
The driving end of the protection circuit is connected to the output end of the comparison circuit, the first output end of the protection circuit with On the circuit that second output terminal is connected on the voltage output end and load is constituted, when the driving termination of the protection circuit receives The first output end of the protection circuit and second output terminal disconnect when the overvoltage protection signal, otherwise, the protection circuit The first output end be connected to second output terminal;
The protection circuit includes triode and photoelectrical coupler;
The base stage of the triode is that the driving end of the protection circuit is connected to the output end of the comparison circuit, three pole The collector of pipe is connected to the anode of the voltage output end and the photoelectrical coupler, the cathode connection of the photoelectrical coupler To grounding point, the collector and emitter of the photoelectrical coupler is respectively that first output end for protecting circuit and second are defeated Outlet is connected on the circuit of the voltage output end and the load composition.
2. circuit according to claim 1, which is characterized in that the reference voltage generating circuit includes first resistor, Two resistance and the first integrated operational amplifier, wherein
The homophase input pin of first integrated operational amplifier is that the input terminal of the reference voltage generating circuit is connected to The output end of the reference voltage generating circuit, the reversed input pin of first integrated operational amplifier are connected to described The first end of one resistance, the first end of the first resistor are connected to the first end of the second resistance, the second resistance Second end is connected to the output pin of first integrated operational amplifier, the output pin of first integrated operational amplifier For the output end of the reference voltage generating circuit, the power pins of first integrated operational amplifier are connected to power supply electricity The grounding pin of source, the second end of the first resistor and first integrated operational amplifier is connected to grounding point.
3. circuit according to claim 2, which is characterized in that the comparison circuit includes the second integrated operational amplifier, Wherein,
The homophase input pin of second integrated operational amplifier is described in the first input end of the comparison circuit is connected to Voltage output end, the reversed input pin of second integrated operational amplifier are that the second input terminal of the comparison circuit connects To the output end of the reference voltage generating circuit, the output pin of second integrated operational amplifier is the comparison circuit Output end be connected to the driving end of the protection circuit, the power pins of second integrated operational amplifier are connected to power supply The grounding pin of power supply, second integrated operational amplifier is connected to ground terminal.
4. circuit according to claim 1, which is characterized in that the reference voltage generating circuit further includes 3rd resistor, Wherein,
The 3rd resistor is connected between the voltage output end and the anode of three end adjustable shunt reference source.
5. circuit according to claim 2, which is characterized in that the reference voltage generating circuit further includes the 4th resistance, Wherein,
4th resistance is connected on the homophase input pin of first integrated operational amplifier and the reference voltage generates Between the output end of circuit.
6. circuit according to claim 1, which is characterized in that the protection circuit further includes the 5th resistance and the 6th electricity Resistance, wherein
5th resistance is connected between the voltage output end and the collector of the triode, the 6th resistance series connection On the circuit that the voltage output end, the first output end of the load and the protection circuit and second output terminal are constituted.
7. a kind of lamps and lanterns with over-voltage protecting function, including DC power supply, light source and as described in any one of claim 1 to 6 Overvoltage crowbar, wherein
The voltage output end of the DC power supply is connected to the input of the reference voltage generating circuit in the overvoltage crowbar It holds, the first output end and second output terminal of the protection circuit in the overvoltage crowbar are connected in series in the DC power supply Voltage output end and the light source constitute circuit on.
CN201310373533.XA 2013-08-23 2013-08-23 A kind of overvoltage crowbar and the lamps and lanterns with over-voltage protecting function CN104426125B (en)

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CN201310373533.XA CN104426125B (en) 2013-08-23 2013-08-23 A kind of overvoltage crowbar and the lamps and lanterns with over-voltage protecting function

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CN201310373533.XA CN104426125B (en) 2013-08-23 2013-08-23 A kind of overvoltage crowbar and the lamps and lanterns with over-voltage protecting function

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CN104426125B true CN104426125B (en) 2019-03-26

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Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106026009A (en) * 2016-05-23 2016-10-12 深圳市华星光电技术有限公司 Overcurrent protection circuit for power manager, and display panel equipped with overcurrent protection circuit

Citations (5)

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CN201927998U (en) * 2010-11-25 2011-08-10 康佳集团股份有限公司 Short circuit protection circuit for LED backlight lamp strings
CN202797874U (en) * 2012-07-03 2013-03-13 青岛海信移动通信技术股份有限公司 Over-voltage protection circuit and mobile terminal
CN102969697A (en) * 2011-09-02 2013-03-13 通嘉科技股份有限公司 Control method for overvoltage protection and control circuit used for power supply controller
CN103001189A (en) * 2012-11-05 2013-03-27 冶金自动化研究设计院 Converter overvoltage and overcurrent fault alarming protective circuit
CN103227568A (en) * 2012-01-26 2013-07-31 凌力尔特公司 Flyback converter with primary side voltage sensing and overvoltage protection during low load operation

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201927998U (en) * 2010-11-25 2011-08-10 康佳集团股份有限公司 Short circuit protection circuit for LED backlight lamp strings
CN102969697A (en) * 2011-09-02 2013-03-13 通嘉科技股份有限公司 Control method for overvoltage protection and control circuit used for power supply controller
CN103227568A (en) * 2012-01-26 2013-07-31 凌力尔特公司 Flyback converter with primary side voltage sensing and overvoltage protection during low load operation
CN202797874U (en) * 2012-07-03 2013-03-13 青岛海信移动通信技术股份有限公司 Over-voltage protection circuit and mobile terminal
CN103001189A (en) * 2012-11-05 2013-03-27 冶金自动化研究设计院 Converter overvoltage and overcurrent fault alarming protective circuit

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