Power-saving and silencing alternating-current contactor

Abstract

The invention relates to a power-saving and silencing alternating-current contactor, which comprises a power-saving unit and an alternating-current contactor, wherein the power-saving unit consists of a voltage control switch circuit composed of a transient voltage suppressor diode, an energy storage circuit composed of a capacitor and a rectifying and energy locking circuit composed of a diode and is a four-port network, input ports of the four-port network are connected with AC (Alternating Current) voltage, and output ports of the four-port network are connected with an excitation coil in the alternating-current contactor.

Description

technical field [0001] The invention relates to the field of low-voltage electrical appliances, in particular to a pulse type AC contactor with the functions of saving electric energy and static noise. Background technique [0002] AC contactor is a low-voltage electrical appliance widely used in electrical equipment. Its working principle is to use the electromagnet to drive the moving contact (moving contact) and the static contact (moving contact) to close or separate, so as to achieve the purpose of connecting or cutting off the circuit. It is suitable for starting or controlling three-phase induction motors and other electrical equipment. [0003] figure 1 It is the working principle diagram of the traditional AC contactor. This traditional AC contactor is mainly composed of a moving iron core, a static iron core, an excitation coil, a return spring, a moving-break contact, and a moving-closing contact. When the excitation coil is connected to AC220V, AC110V or AC38...

AI Technical Summary

Problems solved by technology

[0009]1. Heating: During the pull-in and hold stages, since the excitation coil is passed through the AC voltage (that is, the AC voltage), the moving and static iron cores will Hysteresis loss and eddy current loss will inevitably generate heat, and the heat generated by the moving and static iron cores will affect the excitation coil, and in severe cases, the excitation coil will be burned

In addition, there is a "short-circuit ring" in the small traditional AC contactor. The existence of the short-circuit ring will increase the temperature rise of the contactor and make the excitation coil more likely to burn out.

[0010]2. Power consumption: The heat energy of the traditional AC contactor is the electric energy input into the excitation coil. Another disadvantage brought by this harmful heat is unnecessary power consumption. Electricity

[0011] 3. Noise: Every time the AC voltage input to the excitation coil "crosses zero" (the "zero crossing point" when the AC voltage transitions from a positive half cycle to a negative half cycle or a negative half cycle to a positive half cycle), the electromagnetic attraction changes drastically, which will cause the motor to 1. The silicon steel sheet in the static iron core produces mechanical vibration noise with a frequency of 100Hz (50Hz alternating current) or 120Hz (60Hz alternating current)

[0012] 4. Low power factor

[0014] 1. The structure is complex and difficult to implement; the "AC contactor power saver" controlled by a single-chip microcomputer is susceptible to electromagnetic interference from the AC contactor itself or electrical appliances such as motors, resulting in internal program execution errors and "flying" miscontrol;

[0015]2. There are too many electronic devices and complicated electronic circuits;

[0016] 3. The price of the products produced is too high. For example, the price of the QXJB AC contactor power saver produced by a company in Zhuhai City, Guangdong Province is as high as 1,500 yuan per set! The price of a small AC contactor is only more than 20 yuan, and the price of a medium-sized AC contactor is only a few hundred yuan. Such an expensive "QXJB AC contactor power saver" will make very few users

[0017]4. Due to the complexity of the electronic circuit and the many electronic devices used, it is difficult to integrate the power-saving control part of the AC contactor with the AC contactor. An additional box must be installed for the power-saving control part of the system, which causes inconvenience for users to install and troublesome wiring.

[0018]5. Due to the complex electronic circuit and many electronic devices used, the power consumption of the power saving control part of the AC contactor (AC-DC conversion loss, IC power consumption, actuator power consumption, etc.) will increase

The main reason is that the price of energy-saving contactors is relatively expensive, and users cannot accept the one-time investment. The country needs to increase policy efforts in the promotion of energy-saving contactors to promote the wide application of energy-saving contactors.”

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