AC voltage operation: Under AC or DC voltage, or in combination of DC, you can use all HVC membrane capacitors. The principle of successful application is: 1) Do not exceed the voltage capacity of the dielectric; 2) Keep capacitor cooling; 3) Do not carry corona operation. As a practical application, here is how you use these three rules.

The limiting voltage peak is a rated DC voltage. Limit the product of the current peak in the rating of the amount of capacity and the DV / DT rated value. For high frequency operations to limit power dissipation, so that the temperature rise of the outer casing does not exceed 15 ° C, and at the same time the outer casing temperature is not higher than the maximum operating temperature.

For rule 3, limit the external voltage to each type of maximum AC rating to avoid corona.
Corona is an insulating system in the insulating system to cause dielectric partial breakdown by air pores. Its occurrence is accompanying the application AC voltage because the effective capacitance of the pore is lower than the surrounding dielectric material. As a low-value capacitor is connected in series, the pore is broken by a higher voltage gradient. Corn Dizzy is to be avoided because sparks cause the dielectric carbonization to convert it into a conductor material, and the final carbon travo is short-circuited.

 

RC absorption/snubber circuit design

Surge absorption is a variety of simple energy absorption circuits to eliminate voltage spikes caused by loop inductance ----- When mechanical or semiconductor switches are turned on. The purpose of surge absorption is to remove transient voltages and oscillations that occur when the switch is turned on.
It happens to provide an optional circuit when the current flows in an inherent leakage inductor when the switch is turned on. Sub-absorption in the switch mode power supply provides one or more of the following three important functions:
1) Change the carrier line of a bipolar conversion transistor to keep it in a safe operating area;
2) Remove energy from the steering transistor, consume energy in the resistor to reduce the joint temperature;
3) Reduce oscillation on the switching transistor or rectifier diode to limit the peak voltage, reduce EMI by reducing emission and reducing its frequency