Dc Voltage Spike Protection Circuit

Another very simple form of over voltage protection uses an approach called voltage clamping.

Dc voltage spike protection circuit.

24 v dc 1 2 28 8 v dc. A lower clamping voltage indicates better protection but can sometimes result in a shorter life expectancy for the overall protective system. With the zener diode voltage chosen to be slightly above the maximum rail voltage under normal conditions it will not conduct. 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. In its simplest form it can be provided by using a zener diode placed across the output of the regulated power supply. The main purpose of a voltage suppression circuit is to clamp the voltage to a safe level. Dc input circuits can experience current overload short circuit conditions or voltage transients esd etc and require ptcs multilayer varistors and fuse protection to meet regulatory standards or to ensure reliable operation.

The tvs circuit we will build for dc power is shown below. Click on the green links to find littelfuse circuit protection solutions. 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.

Dc transient voltage suppressor circuit. The zener diode used is rated for 12v. The most common form of voltage clamping devices are metal oxide varistors mov s and zener diodes.