A capacitor employed in power supplies for ripple reduction.
There are a number of applications for a filter capacitor:
- Removing noise or spikes on DC (direct current) power rails or buses
- switching on or off a heater will create a spike on the line
- Brushed DC motors will create noise on the DC line as long as they are switched on
- Removing RFI (Radio frequency interference) from signal or power lines
- After a voltage regulator to smooth DC power supplies
- Arc suppression, such as across the contact breaker or 'points' in a spark-ignition engine