The working principle of porcelain chip capacitor filtering
The filter capacitor has a large capacity, so electrolytic capacitors are generally used, and attention should be paid to the positive and negative terminals of the electrolytic capacitors when wiring. Capacitor filter circuit uses the charging and discharging effect of capacitor to make the output voltage smooth. Film capacitor price, when u2 is positive half-cycle and the value is greater than the voltage uC at both ends of the capacitor, diodes D1 and D3 turn on, D2 and D4 turn off, the current flows through the load resistor RL, and the other way charges the capacitor C.
When uC>u2, it causes D1 and D3 tubes to reverse bias and cut off, the capacitor discharges through the load resistor RL, and uC decreases slowly according to the exponential law. When u2 is negative half-cycle amplitude change to exactly greater than uC, D2 and D4 become on because of the positive voltage, u2 again to C charging, uC rose to the peak of u2 and then began to decline; down to a certain value D2 and D4 become cutoff, C to RL discharge, uC according to the exponential law down; discharge to a certain value D1 and D3 become on, repeat the above process.