Energy accumulation type DC suction and DC keeping circuit for AC contactor

Abstract

The invention relates to a circuit used for energy storage type direct current attracting and direct current keeping of an alternating current contactor. The circuit is formed as follows: a first capacitor is connected with the positive pole of a first diode and the negative pole of a third diode, the negative pole of the first diode is connected with the negative pole of a second diode, the positive pole of the second diode is connected with the negative pole of a fourth diode, and the positive pole of the fourth diode is connected with the positive pole of the third diode; the positive poleof a second capacitor is connected with the negative pole of the first diode, the negative pole of the second diode, and one end of a relay; the other end of the relay is connected with a contactor and the negative pole of a fifth diode, and at the same time the contactor is connected with the positive pole of the third diode, the positive pole of the fourth diode, the negative pole of the secondcapacitor, and one end of a resistance; and the other end of the resistance is connected with the positive pole of the fifth diode. The circuit has a simple structure, the regulation is convenience, no auxiliary contact is needed, the voltage for attracting and keeping is stable, the circuit is suitable for various alternating current contactors, and the reliability of the action of the built-in alternating current contactor of a soft starter can be efficiently improved.

Description

technical field

[0001] The invention relates to a soft starter device, in particular to an energy storage type DC pull-in and DC hold circuit for an AC contactor. Background technique

[0002] There are two types of AC contactors in low-voltage electrical, one works in 220V AC circuits, and the other works in 380V AC circuits. Most of the commercially available ones belong to the first category, and in order to simplify the design in the soft starter, the contactor action must be powered from two of the three phases, so it must work at 380V AC voltage.

[0003] The existing contactor coil directly obtains voltage from 220V AC or 380V AC, the circuit is simple and the cost is low, but the power factor is obviously reduced due to the influence of magnetic hysteresis and eddy current loss in the iron core. When the low voltage (such as 70% of the nominal voltage value) can operate, the high voltage (such as greater than or equal to 15% of the nominal value) is prone to overhea...

Examples

Embodiment Construction

[0032] Below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation, structure and features provided by the present invention are described in detail as follows:

[0033] Through the analysis and research of the existing technical solutions, the present invention proposes a simple and reliable technical solution based on the idea of ​​DC holding and DC pull-in, the principle of which is as follows: image 3 shown.

[0034] In the figure: KM is a contactor, J is a relay, and there are four diodes D1, D2, D3, D4 to form a bridge-type full-wave rectification circuit, which converts alternating current into direct current.

[0035] The specific connection relationship of the circuit is as follows: the first capacitor C1 is connected to the anode of the first diode D1 and the cathode of the third diode D3, and the cathode of the first diode D1 is connected to the cathode of the second diode D2 , the anode of the second diode D2 is conn...

technical field

[0001] The invention relates to a soft starter device, in particular to an energy storage type DC pull-in and DC hold circuit for an AC contactor. Background technique

[0002] There are two types of AC contactors in low-voltage electrical, one works in 220V AC circuits, and the other works in 380V AC circuits. Most of the commercially available ones belong to the first category, and in order to simplify the design in the soft starter, the contactor action must be powered from two of the three phases, so it must work at 380V AC voltage.

[0003] The existing contactor coil directly obtains voltage from 220V AC or 380V AC, the circuit is simple and the cost is low, but the power factor is obviously reduced due to the influence of magnetic hysteresis and eddy current loss in the iron core. When the low voltage (such as 70% of the nominal voltage value) can operate, the high voltage (such as greater than or equal to 15% of the nominal value) is prone to overhea...

Examples

Embodiment Construction

[0032] Below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation, structure and features provided by the present invention are described in detail as follows:

[0033] Through the analysis and research of the existing technical solutions, the present invention proposes a simple and reliable technical solution based on the idea of ​​DC holding and DC pull-in, the principle of which is as follows: image 3 shown.

[0034] In the figure: KM is a contactor, J is a relay, and there are four diodes D1, D2, D3, D4 to form a bridge-type full-wave rectification circuit, which converts alternating current into direct current.

[0035] The specific connection relationship of the circuit is as follows: the first capacitor C1 is connected to the anode of the first diode D1 and the cathode of the third diode D3, and the cathode of the first diode D1 is connected to the cathode of the second diode D2 , the anode of the second diode D2 is conn...

Images