Over-voltage protection circuit

Posted on Oct 26, 2012

A silicon-controlled rectifier is installed in parallel with the 12-V line and connected to a normally-closed 12-V relay, K1. The SCR's gate circuit is used to sample the applied voltage. As long as the applied voltage stays below a given value, SCR1 remains off and Kl's contacts remain closed, thereby supplying power to the load. When the source voltage rises above 12 V, sufficient current is applied to the gate of SCR1 to trigger it into conduction.

Over-voltage protection circuit
Click here to download the full size of the above Circuit.

The trigger point of SCR1 is dependent on the setting of R1. Once SCR1 is triggered (activating the relay), K1's contacts open, halting current flow to the load.

Leave Comment

characters left:

New Circuits



Popular Circuits

Ultra Low Power LCD Indicator
LF Exciter using I2PHD/IK2CZL JASON
Preregulator for power supply
Bootstrap Buffer Based Preamp
Digital To Analog Converter Circuit
EMF Probe Version 2
power-amplifier 2
metal detector project circuit
Mobile Scanner Circuit
Using C-52 EVB for simple robot experiments
Light Alarm Circuit
Digital Remote Thermometer
FireFly Diorama
Forward and reverse running short brake circuit