How do you calculate the capacitor value of a power supply?

How do you calculate the capacitor value of a power supply?


  1. Q = C * V, C = capacitance in farads, Q = charge in coulombs, V = voltage potential.
  2. Q = I * T, I = current flow in amps, Q = charge in coulombs, T = time in seconds.
  3. F = 1 /T, F = frequency in hZ, T = period in seconds.

How do I choose a capacitor for my filter?

The key factors that you should consider when selecting a capacitor for SMPS filtering applications include equivalent series resistance (ESR), equivalent series inductance (ESL), capacitance density, temperature characteristics, dielectric constant, voltage characteristics, frequency characteristics, and cost.

How capacitor works as filter in power supply?

A capacitor-input filter is a filter circuit in which the first element is a capacitor connected in parallel with the output of the rectifier in a linear power supply. The capacitor increases the DC voltage and decreases the ripple voltage components of the output.

How do you select capacitor voltage?

Choose ceramic capacitors with a voltage rating of at least 1.5 times the maximum-input voltage. If tantalum capacitors are selected, they should be chosen with a voltage rating of at least twice the maximum-input voltage.

How do you select a capacitor?

The voltage rating of the capacitor should always be at least 1.5 times or twice the maximum voltage that it may encounter in the circuit. Capacitors are not as reliable as resistors. They get easily damaged once the applied voltage nears their maximum rating.

Which filter is best for power supply?

A good power supply filter can be built from a single inductor and damped capacitor. This is called an LC filter.

How do I choose the right size capacitor?

You mainly need to look at 2 values: the voltage and the capacity -both are written on most capacitors-. For example, if you are going to charge a capacitor with 24V, you need to make sure your capacitor will support that voltage; so you’ll need a capacitor for at least 25V (plus error margin).

Why capacitor filter is used in power supply?

In power supplies, capacitors are used to smooth (filter) the pulsating DC output after rectification so that a nearly constant DC voltage is supplied to the load. Filter capacitors reduce the amount of ripple voltage to a level that is acceptable.

Why capacitor is used in power supply?

Power conditioning Reservoir capacitors are used in power supplies where they smooth the output of a full or half wave rectifier. They can also be used in charge pump circuits as the energy storage element in the generation of higher voltages than the input voltage.