Energy saving type control method of composite switch and energy saving type composite switch

Abstract

The invention discloses an energy saving type control method of composite switch and an energy saving type composite switch. A first terminal of the composite switch is used for connecting with an electric network, a second terminal is used for connecting with an electric power capacitor, a third terminal is used for connecting with one pole of a relay direct-current power source, a fourth terminal is connected with another pole of the relay direct-current power source after being connected with a control switch in series; a bidirectional controllable silicon switch and a relay normally open contact are arranged in parallel between the first terminal and the second terminal; the third terminal and the fourth terminal are respectively internally connected with A,B ends of a relay coil; a fifth terminal is directly connected with the same pole of the direct-current power source connected with the fourth terminal; a capacitor is connected between the fifth terminal and the A end of the coil; a resistor is connected between the A end of the coil and the third terminal. Because the current across the relay coil is greatly reduced after applying the electric power capacitance, the heating amount of the coil is obviously reduced and furthermore the whole work reliability of the relay and the composite switch is greatly increased.

Description

technical field [0001] The invention relates to the field of low-voltage electrical appliances, and more specifically relates to an energy-saving control method of a composite switch and an energy-saving composite switch. Background technique [0002] The composite switch is a device used to control the switching of power capacitors. Its working principle is to connect the thyristor (thyristor) switch and the contact of the relay in parallel to connect the circuit, so that the thyristor will go through zero at the moment of capacitor input and removal. Switching, that is, when the voltage crosses zero when the voltage is zero, the thyristor first crosses zero and triggers conduction, and then the relay contacts are turned on after stabilization. When cutting out, the thyristor is first turned on, and the relay contacts Then it is disconnected, and the thyristor delays the zero-crossing disconnection, so as to realize the cut-off when the current is zero-crossing. Since the ...

AI Technical Summary

Problems solved by technology

[0004] In addition, in the prior art, most of the coils of electromagnetic relays are directly connected to the power supply (or directly through series-connected control switches). Therefore, in the working state, the magnitude of the current passing through the coil before and after the contacts are pulled is consistent

Since the holding current of the relay coil used to maintain the contact pull-in after the contact pull-in is usually much smaller than the pull-in instant current, therefore, continuing to pass the original high current to the relay coil after the contact pull-in will not only cause waste of electric energy, Moreover, the relay coil will also reduce the service life of the relay due to the high heat generation, especially the high-power electromagnetic relay with non-frequent opening and closing of contacts.

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