The electromagnetic vibrating feeder is a kind of equipment which can control the amount of material, which can achieve uniform and convenient control of production. By adjusting the amplitude to realize automatic control the feeding amount, vibrating at the frequency of 3000 times/min, through silicon controlled single-phase half-wave rectifier circuit, electromagnetic vibrator supply a kind of adjustable to the size of the pulsating direct current, so as to realize control of direct current (dc) size and can control the amplitude of the size.

The amplitude adjustment method of electromagnetic vibrating feeder generally contain following types:

1. Voltage type amplitude regulator.
This kind of regulator uses the voltage regulator to adjust the voltage, which is limited to the capacity of the voltage regulator by semi-wave rectification, which applicable to the small electromagnetic vibration feeder. Although the regulator structure is relatively simple, the adjustment range is large, but it is not easy to realize automatic control.

2. Resistance type amplitude regulator.
The principle of this regulator to regulate the amplitude of the electromagnetic vibration feeder is to change the load resistance value to change the input voltage of the electric vibrating feeder.  

3. Variable induction regulator.
The advantage of this regulator is that the regulation features are smooth and the loss is small, but the power factor is low.

4. Variable capacitor regulator.
This kind of regulator is generally used only for micro electromagnetic vibration feeder, although the power factor is high, but the regulation characteristic is poor.  

5. Thyristor rectifying regulator.
The thyristor half-wave rectifier control scheme is ideal for the electromagnetic vibrating feeder amplitude regulator. Its advantage is that the range of adjustment is large, and the range of adjustment can be achieved from zero to rating. The closed-loop control can achieve high control precision. The power consumption of the control system is very small, which can be considered to be lossless, especially for medium and large electromagnetic vibration feeders. In addition, the controller has the advantages of low cost, small volume and simple structure. 

Considering the advantages and disadvantages of the above-mentioned controllers, it is widely used to adjust the amplitude realization to the material, which is simple and feasible and easy to realize automatic control. Thyristor trigger circuit is also in development, from the simple rc phase shift trigger circuit, unijunction transistor trigger circuit, application-specific integrated circuit trigger circuit to the current intelligent digital trigger circuit based on MCU. By single chip microcomputer control of its amplitude control not only has the advantages of convenient, simple and flexible, but also can raise the technical index of accused of amplitude, which can greatly improve the control precision of the equipment transfer materials.