CN202749803U - Short-circuit protection circuit for direct-current power supply having function of pre-charging - Google Patents
Short-circuit protection circuit for direct-current power supply having function of pre-charging Download PDFInfo
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- CN202749803U CN202749803U CN 201220198978 CN201220198978U CN202749803U CN 202749803 U CN202749803 U CN 202749803U CN 201220198978 CN201220198978 CN 201220198978 CN 201220198978 U CN201220198978 U CN 201220198978U CN 202749803 U CN202749803 U CN 202749803U
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- power supply
- current sensor
- voltage
- voltage comparator
- hall current
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Abstract
The utility model discloses a short-circuit protection circuit of a direct-current power supply having a function of pre-charging. The short-circuit protection circuit comprises an MCU, a Hall current sensor, a voltage comparator, an opto-coupler, a pre-charging switch, a discharge switch and a direct-current regulated power supply for powering the Hall current sensor, the voltage comparator and the opto-coupler. When the direct-current power supply begins to discharge, the MCU controls the discharge switch to be switched on, and the pre-charging switch is switched off for a certain time and then switched on; the direct-current regulated power supply begins to supply power for the Hall current sensor, and the Hall current sensor samples a discharging current of a direct-current power supply output circuit and converts the sample into a voltage value; the voltage value is filtered by a filtering capacitor and sent to a cocurrent comparison end of the voltage comparator, and a reference voltage is connected to a reverse comparison end of the voltage comparator; and an output level of the voltage comparator drives a triode to conduct so as to open the light coupler and control the discharge switch to be switched off, thereby cutting off a discharge circuit. The short-circuit protection circuit provided by the utility model has the advantages of low power consumption and high precision.
Description
Technical field
The utility model relates to the short-circuit protection circuit field, is specifically related to a kind of short-circuit protection circuit with DC power supply of pre-charging functions.
Background technology
DC power supply is the power supply of electric automobile and UPS equipment, when DC power supply is short-circuited, must cut off discharge loop, guarantees the safety of power supply self and power consumption equipment thereof.Existing protective circuit is to utilize the method for resistance sampling, and current signal is converted into voltage signal, and has certain threshold value through row relatively, if greater than this value, we are considered as short circuit with it, thereby the switching device of control back cuts off discharge loop.
At present; electric automobile and UPS equipment much are capacitive loads, and the direct current power discharge immediate current is very large, and easily wrong report is short circuit; simultaneously because the electric current of the work of electric automobile and UPS equipment reaches tens even the hundreds of ampere, existing short-circuit protection circuit just is not easy to choose resistance.
The utility model content
When the utility model purpose is to provide a kind of discharge for lithium battery or storage battery, capacitive load is carried out precharge, and the short-circuit protection circuit of the DC power supply with pre-charging functions of when short circuit occurring, protecting.
Short-circuit protection circuit with DC power supply of pre-charging functions; include the DC power supply with pre-charging functions; the two ends access power consumption equipment of described DC power supply; be connected with discharge switch S2 between the positive pole of described DC power supply and the power consumption equipment; it is characterized in that: also include micro-control unit MCU; Hall current sensor; voltage comparator U2; optocoupler U1; precharge switch S1 and be respectively Hall current sensor; voltage comparator U2; the D.C. regulated power supply VCC of optocoupler U1 power supply; D.C. regulated power supply VCC obtains a magnitude of voltage after by the divider resistance dividing potential drop and gives on the P terminal as reference voltage; described Hall current sensor places on the power consumption equipment; be connected with precharge switch S1 between the voltage output end of the feeder ear of Hall current sensor and D.C. regulated power supply VCC; described MCU and precharge switch S1; discharge switch S2 control connection; Hall current sensor is converted into voltage signal with the discharging current that collects and exports from signal output part; the positive pole of an anti-reverse diode D1 of signal output part access of Hall current sensor; the negative pole of anti-reverse diode D1 is connected with a balance resistance R2; Nodes between the signal output part of Hall current sensor and the anti-reverse diode D1 is connected to a filter capacitor C1; the other end ground connection of filter capacitor C1; through filtered voltage signal relatively holding in the same way by balance resistance R2 access voltage comparator; the reference voltage signal of P terminal is oppositely relatively held by balance resistance R4 access voltage comparator U2's; the base stage of the triode Q1 of output access of voltage comparator U2; the grounded emitter of triode Q1; the collector electrode of triode Q1 is by 2 pin of a Light-Emitting Diode LED access optocoupler U1; the control end of the 3 pin access discharge switch S2 of optocoupler U1,1 pin of optocoupler U1; be connected with respectively current-limiting resistance R1 between 4 pin and the D.C. regulated power supply VCC; R3.
Described DC power supply with pre-charging functions is lithium battery or storage battery.
Operation principle of the present utility model is:
In the moment that DC power supply begins to discharge, MCU sends control signal, and precharge switch S1 is disconnected, and Hall current sensor is not because there being Power supply, therefore cisco unity malfunction.Simultaneously, MCU enables discharge switch S2, and discharge switch S2 is just closed.Even DC power supply is charged to its capacitive load like this, immediate current is very large, and Hall current sensor also can't detect, and can not produce because DC power supply large and phenomenon of wrong report short circuit of immediate current during to the precharge of its capacitive load.
Behind the direct current power discharge one-period, S1 is closed for MCU control precharge switch, D.C. regulated power supply VCC powers to Hall current sensor, Hall current sensor is converted into voltage signal with the current signal that detects, this voltage signal is delivered to the in the same way end relatively of voltage comparator U2 in the short-circuit detecting circuit after through filtering capacitor C 1 and anti-reverse diode D1, the reference level of oppositely relatively holding with voltage comparator U2 compares, after signal exceeds normal range (NR), then be considered as short circuit, this moment, the output of voltage comparator U2 produced a high level, this level makes the triode Q1 conducting that links to each other with voltage comparator U2 output, optocoupler U1 work this moment.The output of optocoupler U1 links to each other with discharge switch S2, and at this moment discharge switch S2 disconnects, and cuts off discharge loop, and circuit is protected short circuit phenomenon.
Good effect of the present utility model is:
1) the utility model has solved the problem to the capacitive load discharge; when load is capacitive; the immediate current of lithium battery discharge can be very large, and it is short trouble that general short-circuit protection circuit generally can be thought by mistake, and this circuit has solved this problem well by pre-charge circuit.
2) the utility model adopts Hall current sensor to carry out contactless current sample, sample circuit (power consumption can be controlled in the 0.5W) low in energy consumption, precision high (current error is rated current scope ± 1%);
Description of drawings
Fig. 1 is circuit theory diagrams of the present utility model.
Embodiment
As shown in Figure 1; short-circuit protection circuit with DC power supply of pre-charging functions; include the DC power supply 1 with pre-charging functions; the two ends access power consumption equipment 2 of DC power supply 1; be connected with discharge switch S2 between the positive pole of DC power supply 1 and the power consumption equipment 2; also include micro-control unit MCU; Hall current sensor 3; voltage comparator U2; optocoupler U1; precharge switch S1 and be respectively Hall current sensor 3; voltage comparator U2; the D.C. regulated power supply VCC of optocoupler U1 power supply; D.C. regulated power supply VCC obtains a magnitude of voltage after by the divider resistance dividing potential drop and gives on the P terminal as reference voltage; Hall current sensor 3 places on the power consumption equipment 2; be connected with precharge switch S1 between the voltage output end of the feeder ear of Hall current sensor 3 and D.C. regulated power supply VCC; MCU and precharge switch S1; discharge switch S2 control connection; Hall current sensor 3 is converted into voltage signal with the discharging current that collects and exports from signal output part; the positive pole of an anti-reverse diode D1 of signal output part access of Hall current sensor 3; the negative pole of anti-reverse diode D1 is connected with a balance resistance R2; Nodes between the signal output part of Hall current sensor and the anti-reverse diode D1 is connected to a filter capacitor C1; the other end ground connection of filter capacitor C1; through filtered voltage signal relatively holding in the same way by balance resistance R2 access voltage comparator; the reference voltage signal of P terminal is oppositely relatively held by balance resistance R4 access voltage comparator U2's; the base stage of the triode Q1 of output access of voltage comparator U2; the grounded emitter of triode Q1; the collector electrode of triode Q1 is by 2 pin of a Light-Emitting Diode LED access optocoupler U1; the control end of the 3 pin access discharge switch S2 of optocoupler U1,1 pin of optocoupler U1; be connected with respectively current-limiting resistance R1 between 4 pin and the D.C. regulated power supply VCC; R3.
When DC power supply 1 begins to discharge, by 2 conductings of MCU controlled discharge switch S, turn-off simultaneously precharge switch S1 certain hour, like this within a period of time of discharge beginning, Hall current sensor 3 cisco unity malfunctions.Therefore when capacitive load was discharged, immediate current was very large, short-circuit protection circuit is not protected this moment yet.After discharge loop discharge certain hour, MCU control precharge switch S1 conducting, D.C. regulated power supply VCC begins to be Hall current sensor 3 power supplies, the discharging current of 3 pairs of DC power supply 1 output loops of Hall current sensor this moment is sampled, and convert magnitude of voltage to, this magnitude of voltage is delivered to the anode of anti-reverse diode D1 through the filtering of capacitor C 1.At this moment voltage is delivered to relatively holding in the same way of voltage comparator U2 through balance resistance R2, as the input signal of short-circuit protection circuit.The P terminal is received oppositely relatively holding of voltage comparator through balance resistance R4, as reference voltage.The output level of this voltage comparator drives the conducting of triode Q1, and then optocoupler U1 is opened, and discharge loop is cut off in the like this shutoff of controlled discharge switch.
The precharge control pin of MCU links to each other with precharge switch S1, the control of discharge pin links to each other with discharge switch S2, the output of Hall current sensor 3 links to each other with relatively holding in the same way of voltage comparator U2, and the output of voltage comparator U2 links to each other with the base stage of triode Q1, the collector electrode of triode Q1 is connected with the LED lamp, and LED mainly is the working condition that is used to refer to optocoupler.It is connected to 2 pin of optocoupler, and 1 pin of optocoupler links to each other with resistance R 1, is connected on the D.C. regulated power supply VCC.4 pin of while optocoupler link to each other with resistance R 3 and also are connected on the D.C. regulated power supply VCC, and at this moment 3 pin of optocoupler come the shutoff of controlled discharge switch S 2.
When powering for DC power supply 1 to capacitive load; the moment that DC power supply 1 begins to discharge; the electric current of discharge loop is very large; but at this moment MCU control precharge switch S1; make its shutoff; D.C. regulated power supply VCC can't give Hall current sensor 3 power supplies, and can't detect electric current this moment, thereby the short-circuit protection circuit of avoiding carries out short-circuit protection owing to immediate current is excessive.
When DC power supply 1 is short-circuited phenomenon, the immediate current of discharge loop is very large, Hall current sensor 3 converts current value to magnitude of voltage, and this magnitude of voltage is delivered to the in the same way end relatively of voltage comparator U2 through filtering capacitor C 1, anti-reverse diode D1, balance resistance R3, at this moment the output valve magnitude of voltage of Hall current sensor 3 can be higher, and it can compare with the reference voltage level of oppositely relatively holding of voltage comparator U2.Owing to having set the threshold value of short-circuit protection in advance, the magnitude of voltage by Hall current sensor 3 outputs during short circuit is certain to be higher than the threshold value of setting, is high thereby make the level of voltage comparator U2 output.The triode Q1 that this high level will drive the back makes its conducting, and the Light-Emitting Diode of the input of optocoupler U1 becomes conducting by cut-off like this, can cause like this output conducting of optocoupler U1, thus 2 shutoffs of controlled discharge switch S, and then cut off discharge loop.
Claims (2)
1. short-circuit protection circuit with DC power supply of pre-charging functions; include the DC power supply with pre-charging functions; the two ends access power consumption equipment of described DC power supply; be connected with discharge switch S2 between the positive pole of described DC power supply and the power consumption equipment; it is characterized in that: also include micro-control unit MCU; Hall current sensor; voltage comparator U2; optocoupler U1; precharge switch S1 and be respectively Hall current sensor; voltage comparator U2; the D.C. regulated power supply VCC of optocoupler U1 power supply; D.C. regulated power supply VCC obtains a magnitude of voltage after by the divider resistance dividing potential drop and gives on the P terminal as reference voltage; described Hall current sensor places on the power consumption equipment; be connected with precharge switch S1 between the voltage output end of the feeder ear of Hall current sensor and D.C. regulated power supply VCC; described MCU and precharge switch S1; discharge switch S2 control connection; Hall current sensor is converted into voltage signal with the discharging current that collects and exports from signal output part; the positive pole of an anti-reverse diode D1 of signal output part access of Hall current sensor; the negative pole of anti-reverse diode D1 is connected with a balance resistance R2; Nodes between the signal output part of Hall current sensor and the anti-reverse diode D1 is connected to a filter capacitor C1; the other end ground connection of filter capacitor C1; through filtered voltage signal relatively holding in the same way by balance resistance R2 access voltage comparator; the reference voltage signal of P terminal is oppositely relatively held by balance resistance R4 access voltage comparator U2's; the base stage of the triode Q1 of output access of voltage comparator U2; the grounded emitter of triode Q1; the collector electrode of triode Q1 is by 2 pin of a Light-Emitting Diode LED access optocoupler U1; the control end of the 3 pin access discharge switch S2 of optocoupler U1,1 pin of optocoupler U1; be connected with respectively current-limiting resistance R1 between 4 pin and the D.C. regulated power supply VCC; R3.
2. the short-circuit protection circuit with DC power supply of pre-charging functions according to claim 1, it is characterized in that: described DC power supply with pre-charging functions is lithium battery or storage battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220198978 CN202749803U (en) | 2012-05-05 | 2012-05-05 | Short-circuit protection circuit for direct-current power supply having function of pre-charging |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220198978 CN202749803U (en) | 2012-05-05 | 2012-05-05 | Short-circuit protection circuit for direct-current power supply having function of pre-charging |
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| Publication Number | Publication Date |
|---|---|
| CN202749803U true CN202749803U (en) | 2013-02-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220198978 Withdrawn - After Issue CN202749803U (en) | 2012-05-05 | 2012-05-05 | Short-circuit protection circuit for direct-current power supply having function of pre-charging |
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| CN (1) | CN202749803U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102709882A (en) * | 2012-05-05 | 2012-10-03 | 安徽力高新能源技术有限公司 | Short circuit protection circuit of direct current power supply provided with precharging function |
| CN105318895A (en) * | 2014-06-20 | 2016-02-10 | 宝山钢铁股份有限公司 | Steel wire liner conveyor belt joint sensing device |
| CN106505698A (en) * | 2017-01-03 | 2017-03-15 | 青岛海信移动通信技术股份有限公司 | Method of supplying power to and electric supply installation |
-
2012
- 2012-05-05 CN CN 201220198978 patent/CN202749803U/en not_active Withdrawn - After Issue
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102709882A (en) * | 2012-05-05 | 2012-10-03 | 安徽力高新能源技术有限公司 | Short circuit protection circuit of direct current power supply provided with precharging function |
| CN102709882B (en) * | 2012-05-05 | 2014-12-03 | 安徽力高新能源技术有限公司 | Short circuit protection circuit of direct current power supply provided with precharging function |
| CN105318895A (en) * | 2014-06-20 | 2016-02-10 | 宝山钢铁股份有限公司 | Steel wire liner conveyor belt joint sensing device |
| CN106505698A (en) * | 2017-01-03 | 2017-03-15 | 青岛海信移动通信技术股份有限公司 | Method of supplying power to and electric supply installation |
| CN106505698B (en) * | 2017-01-03 | 2020-08-14 | 青岛海信移动通信技术股份有限公司 | Power supply method and power supply device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20130220 Effective date of abandoning: 20141203 |
|
| RGAV | Abandon patent right to avoid regrant |