Dc Voltage Spike Protection Circuit

Given that no varistors have a voltage.

Dc voltage spike protection circuit.

The most common form of voltage clamping devices are metal oxide varistors mov s and zener diodes. Dc transient voltage suppressor circuit. Mov s are best suited for protection on bidirectional ac power supplies while zener diodes are best suited for smaller low energy dc supplies. Here in this circuit a 9v dc source is feeding the load which is a dc motor.

This means that if the circuit were to receive voltage above 12v the zener diode would then break down and begin conducting. A lower clamping voltage indicates better protection but can sometimes result in a shorter life expectancy for the overall protective system. The zener diode used is rated for 12v. The tvs circuit we will build for dc power is shown below.

With the zener diode voltage chosen to be slightly above the maximum rail voltage under normal conditions it will not conduct. In its simplest form it can be provided by using a zener diode placed across the output of the regulated power supply. To find the voltage rating of the mov allow for 20 headroom to account for voltage swell and power supply tolerances. Also known as the let through voltage this specifies what spike voltage will cause the protective components inside a surge protector to short or clamp.

Another very simple form of over voltage protection uses an approach called voltage clamping. 24 v dc 1 2 28 8 v dc. Littelfuse is the world leader in circuit protection products and services offering.