Smart Capacitor Supply

Which capacitor should I use for my power supply?

Capacitive power supplies designed for long load life require capacitors with foils and dimensions specifically designed for this application. For its capacitance stability and ruggedness, we recommend using THB film capacitors like the Würth supply applications.

What is a good capacitance for a capacitor?

Capacitance variation due to operating voltage and temperature must be very low to keep the available load current stable. Capacitance drop during the lifetime of the capacitor must also be kept very low. For most applications with this topology, the input capacitance will be between 100 nF and 1000 nF.

Can X2 capacitors be used as a power supply?

In theory class X2 capacitors are electrically suited for that but this is not the intended use of X2 capacitors as defined by IEC-60664-1. Many capacitor manufacturers do not recommend X2 capacitors for these applications, while some permit the use or offer alternative series for capacitive power supply.

Why do smart electricity meters use super capacitors?

In order to support this requirement, smart electricity meters typically use super capacitors to store the required energy. Super capacitors provide good energy density per cm3, and are easily recharged once mains power is restored, making them a popular choice compared to batteries.

What is a 100 nF ideal capacitor at 50 Hz?

example, a 100 nF ideal capacitor at 50 Hz will have about Zideal@50Hz = X@50Hz = 31 831 Ω. We can call this a capacitive dropper circuit. The reactance of the capacitor is taking the burden of the voltage so we are not dissipating energy like in the resistive voltage divider.

Can a capacitive power supply have a low power factor?

The low power factor is not an issue because the capacitive power supply power rating is not high enough for a power factor correction (PFC) to be required. The Standard IEC 61000-3-2 requires PFC for power supplies only with a power output of more than 25 W. 04. CONSTRUCTION OF A CAPACITIVE POWER SUPPLY