CN2315690Y - AC load protector - Google Patents
AC load protector Download PDFInfo
- Publication number
- CN2315690Y CN2315690Y CN 97205405 CN97205405U CN2315690Y CN 2315690 Y CN2315690 Y CN 2315690Y CN 97205405 CN97205405 CN 97205405 CN 97205405 U CN97205405 U CN 97205405U CN 2315690 Y CN2315690 Y CN 2315690Y
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- circuit
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Abstract
The utility model relates to an AC load protector. The utility model comprises a current sample circuit, a rectification voltage stabilizing circuit, an anti-start unwanted operation circuit, a sampling circuit, a comparison circuit and a control circuit, wherein, the current sample circuit senses the current signal from a circuit using electricity and then outputs the current signal to the rectification voltage stabilizing circuit. The current regulator outputs the direct current, one of which is output to the input terminal of the comparison circuit and the control circuit, while the other, as a signal, is output to the sampling circuit, and the sampling circuit outputs the signal to the other input terminal of the comparison circuit. The comparison circuit outputs the signal to the control circuit to control the contactor of the circuit using electricity to operate. The utility model has the advantages that the utility model can be used for protecting the electric appliance from overload, short circuit and load loss, and the utility model has reliable operation, simple structure, low cost and wide use.
Description
The utility model belongs to the emergency protective device technical field.
In the AC load circuit, often load protection circuit need be set, to avoid overlond running.Prior art often adopts voltage sampling as actuating signal, often can not action message, do not have protective effect.
The purpose of this utility model is to provide a kind of load protector that adopts current sampling circuit sampling, comparison circuit to differentiate.
The purpose of this utility model is achieved in that a kind of AC load protective device, comprises current sampling circuit, anti-starting malfunction circuit, regulator rectifier circuit, sample circuit, comparison circuit and control circuit.Current sampling circuit comprises current transformer secondary winding, load resistance, current transformer is experienced arbitrary phase load electric current as sampled signal, the secondary winding electric current passes through load resistance, the voltage that the load resistance two ends produce exports the input of regulator rectifier circuit to, the direct voltage of rectifier output, be divided into two-way, one tunnel input that exports comparison circuit after voltage stabilizing to is as reference voltage and control circuit, and another road exports the sample circuit input to as signal voltage.Current sampling circuit comprises overload sample circuit, short circuit sample circuit and loses a year sample circuit, comparison circuit comprises overload comparison circuit, short circuit comparison circuit and loses a year comparison circuit, and the output of each sample circuit is connected to another input of corresponding comparison circuit.The output of each comparison circuit is connected in parallel and exports the input of control circuit to.Control circuit comprises OR circuit, triode and relay, the signal of the DC voltage-stabilizing of regulator rectifier circuit output and comparison circuit output is imported two inputs of OR circuit respectively, the base stage of the output termination triode of OR circuit, the coil circuit of triode control relay, the coil circuit of the normally opened contact control power circuit contactor of relay.Anti-starting malfunction circuit comprises bidirectional triode thyristor in parallel with load resistance and parallel resistance; and the circuits for triggering that constitute by the series connection of current-limiting resistance and voltage stabilizing didoe; circuits for triggering are experienced the voltage signal of current sampling circuit; during starting under the effect of starting current signal; the voltage that produces on the circuits for triggering can puncture voltage stabilizing didoe makes the bidirectional triode thyristor conducting; parallel resistance is in parallel with the load resistance of current sampling circuit; reduce the output voltage of current sampling circuit, protective device can not produce misoperation.
The utility model has the advantages that, reliable operation, simple in structure, low cost of manufacture, protection is carried in the overload, short circuit, the mistake that can be used as AC electric appliance, and is of many uses.
Fig. 1 is a structure chart of the present utility model, and Fig. 1 is described as follows: 1 is current sampling circuit, and 2 is regulator rectifier circuit, 3 are anti-starting malfunction circuit, 4 is sample circuit, and 5 is comparison circuit, and 6 is control circuit, 7 are the overload sample circuit, 8 are the short circuit sample circuit, and 9 for losing a year sample circuit, and 10 are the overload comparison circuit, 11 are the short circuit comparison circuit, and 12 for losing a year comparison circuit.Fig. 2 is the embodiment basic circuit diagram, and Fig. 2 is described as follows: 13 are the current transformer secondary winding, and 14 is load resistance, 15 is bidirectional triode thyristor, 16 is parallel resistance, and 17 is current-limiting resistance, and 18 is voltage stabilizing didoe, 19 is OR circuit, 20 is triode, and 21 is relay, and 22 is the power circuit contactor, 23 is starting button, and 24 is stop button.
Fig. 2 is the embodiment basic circuit diagram, embodiment is described as follows: the elementary winding of current transformer is experienced the load current of arbitrary phase in the power circuit, the induced electromotive force that its secondary winding produces produces load voltage during by load resistance and falls, it is direct voltage that load voltage falls through rectifier rectification, this voltage is divided into two-way output, one the tunnel provides the overload comparison circuit after voltage stabilizing, the reference voltage of the positive input terminal of the negative input end of short circuit comparison circuit and mistake year comparison circuit and OR circuit and the direct voltage of control circuit, the signal that another road input sampling circuit changes as the reflected load electric current, wherein, overload sample circuit output overloading current signal is to transshipping the positive input terminal of comparison circuit, the short circuit current signal of short circuit sample circuit output is to the positive input terminal of short circuit comparison circuit, lose the mistake live stream signal that carries sample circuit output and extremely lose the negative input end that carries comparison circuit, the potentiometer in the sample circuit can be set overload, short circuit, lose the operation voltage value of carrying.The output that comparison circuit is carried in overload comparison circuit, short circuit comparison circuit and mistake respectively is connected an isolating diode, is connected in parallel the negative input end of input OR circuit then.Under non-failure conditions, the output of each comparison circuit is low level, when breaking down, some high level of promptly exporting in three comparison circuits, this high level signal input OR circuit input makes its output output low level, triode ends, the relay outage in the control circuit.The normally opened contact of the controlled circuit relay electrical equipment of power circuit contactor coil circuit and the control of the normally opened contact of self, when protective device is operated in fault-free conditions following time, OR circuit output high level in the control circuit, make the triode conducting, relay work, if press starting button this moment, normally opened contact and relay normally open contact maintenance that contactor is promptly switched on and inhaled down and pass through self; If overload, short circuit, mistake are carried the sample circuit output signal when reaching set point, OR circuit is an output low level, and triode ends, the relay outage, thus electricity consumption circuit contacts device is disconnected, electrical appliance quits work.The circuits for triggering of anti-starting malfunction circuit comprise voltage stabilizing didoe and current-limiting resistance, the control utmost point of control bidirectional triode thyristor.In the course of normal operation that starting finishes, not conducting of bidirectional triode thyristor, the parallel resistance no current passes through.In starting process; because starting current is the several times of normal load electric current; produce very big voltage drop on the load resistance; voltage stabilizing didoe is punctured; the bidirectional triode thyristor conducting, load resistance is in parallel with parallel resistance, and values of circuit resistances is reduced; output voltage signal reduces, and can not cause the misoperation of protective device.
Claims (1)
1, a kind of AC load protective device comprises current sampling circuit (1), regulator rectifier circuit (2), it is characterized in that also comprising anti-starting malfunction circuit (3), sample circuit (4), comparison circuit (5) and control circuit (6); Current sampling circuit (1) comprises current transformer secondary winding and load resistance, current transformer is experienced arbitrary phase load electric current as sampled signal, the secondary winding electric current passes through load resistance, the voltage that the load resistance two ends produce exports the input of regulator rectifier circuit (2) to, the direct voltage of rectifier output is divided into two-way, one tunnel input that exports comparison circuit (5) after voltage stabilizing to is as reference voltage and control circuit, and another road exports the input of sample circuit (4) to as signal voltage; Sample circuit (4) comprises overload sample circuit (7), a sample circuit (9) is carried in short circuit sample circuit (8) and mistake, comparison circuit (5) comprises overload comparison circuit (10), short circuit comparison circuit (11) and loses a year comparison circuit (12), the output of each sample circuit (7), (8), (9) is connected to another input of corresponding comparison circuit (10), (11), (12), and the output of each comparison circuit (10), (11), (12) is connected in parallel and exports the input of control circuit (6) to; Control circuit (6) comprises OR circuit, triode and relay, the signal of the DC voltage-stabilizing of regulator rectifier circuit (2) output and comparison circuit (5) output is imported two inputs of OR circuit respectively, the base stage of the output termination triode of OR circuit, the coil circuit of triode control relay, the coil circuit of the normally opened contact control power circuit contactor of relay; Anti-starting malfunction circuit (3) comprises and the bidirectional triode thyristor of load resistance parallel connection and parallel resistance and the circuits for triggering of being connected and being constituted by current-limiting resistance and voltage stabilizing didoe; circuits for triggering are experienced the voltage signal of current sampling circuit (1); during starting under the effect of starting current signal; the voltage that produces on the circuits for triggering can puncture voltage stabilizing didoe; make the bidirectional triode thyristor conducting; parallel resistance is in parallel with load resistance; reduce the output voltage of current sampling circuit (1), protective device can not produce misoperation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 97205405 CN2315690Y (en) | 1997-11-06 | 1997-11-06 | AC load protector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 97205405 CN2315690Y (en) | 1997-11-06 | 1997-11-06 | AC load protector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2315690Y true CN2315690Y (en) | 1999-04-21 |
Family
ID=33925636
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 97205405 Expired - Fee Related CN2315690Y (en) | 1997-11-06 | 1997-11-06 | AC load protector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2315690Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104834343A (en) * | 2015-04-02 | 2015-08-12 | 来安县新元机电设备设计有限公司 | Load protection circuit and device |
| CN107968378A (en) * | 2017-11-15 | 2018-04-27 | 芜湖乐佳自动化机械有限公司 | A kind of circuit protection device of electric power system |
-
1997
- 1997-11-06 CN CN 97205405 patent/CN2315690Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104834343A (en) * | 2015-04-02 | 2015-08-12 | 来安县新元机电设备设计有限公司 | Load protection circuit and device |
| CN107968378A (en) * | 2017-11-15 | 2018-04-27 | 芜湖乐佳自动化机械有限公司 | A kind of circuit protection device of electric power system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |