What is Capacitor Filter Circuit? – Diagram, Working, Merits | New Topic [2024]

In this note, we are going to learn about Capacitor Filter Circuit in Rectifier. About its circuit diagram, working principle, advantages as well. Welcome to Poly Notes Hub, a leading destination for polytechnic notes for diploma engineering students.

Author Name: Arun Paul.

What is Capacitor Filter Circuit?

An electronic circuit called a Capacitor Filter Circuit is used in power supply systems to reduce or completely remove ripple voltage in rectifiers‘ output. It is made out of a capacitor that is parallel to the load, which is usually a load circuit or resistor.

Capacitor Filter Circuit Diagram

• Rectifier: Typically, a rectifier circuit sets up the capacitor filter circuit. Rectifiers are devices that transform alternating current voltage into pulsing direct current. Half-wave, full-wave (bridge), and center-tap rectifiers are some of the most common types.
• Capacitor: The capacitor itself serves as the heart of the capacitor filter circuit. This capacitor is linked in parallel with the load (often a resistor or a load circuit). It is usually an electrolytic capacitor since it can handle larger capacitance and voltage levels. The capacitor’s primary function is to store charge and smooth out pulsing DC voltages.
• Load: The device or circuitry that draws electricity from the power supply is known as the load. It is linked to the capacitor in parallel. The load is subsequently fed the DC (Direct Current) voltage that has been smoothed out by the capacitor filter circuit.

Capacitor Filter Working Principle

The rectifier charges the capacitor to its peak voltage during the input AC voltage’s positive half-cycle. The capacitor discharges during the negative half-cycle, delivering current to the load and assisting in the maintenance of a more steady output voltage. The capacitor’s charging and discharging process evens out the output voltage and lowers voltage ripple.

The capacitance value of the capacitor and the load current determine how effective a capacitor filter circuit is. Better filtering is achieved with bigger capacitance values, although larger and more costly capacitors may be needed. On the other hand, output voltage smoothing may not be sufficiently achieved with smaller capacitance values.

Advantages of Capacitor Filter in Rectifier

Here we listed some important advantages of this circuit in rectifier –

1. Reduces ripple to smooth out the output voltage.
2. Easy to implement in rectifier circuit.
3. It is minimize power loss.
4. Easily work with wide range of loads.
5. Quickly adjust to the load.