Over-Voltage Automatic Switch off Circuit

Over-voltage Protection circuit using TL431 Shunt Regulator IC

This circuit protects from high voltage. Automatic Equipment disconnect when the power cross the level of a fixed voltage. This is safety device to overvoltage .

As per datasheet -  TL431A is the three-terminal programmable integrated circuit . This is a shunt regulator diode. Look like a transistor. This monolithic IC voltage references operate as a low temperature coefficient zener which is programmable from Vref to 36 V with two external resistors. This device exhibit a wide operating current range of 1.0 mA to 100 mA with a typical dynamic impedance of 0.22 W. The characteristics references make it excellent replacements for zener diodes in many applications such as digital voltmeters, power supplies, and op amp circuitry. The 2.5 V reference makes it convenient to obtain a stable reference from 5.0 V logic supplies, and since the TL431, A, B operates as a shunt regulator, it can be used as either a positive or negative voltage reference. Active output circuitry provides a very sharp turn-on.
• Typical Temperature Drift (TL431B) characteristic,

  • Programmable Output Voltage to 36 V
  • Voltage Reference Tolerance: +/- 0.4%, Typ @ 25°C (TL431B)
  • Low Dynamic Output Impedance, 0.22 W Typical
  • Sink Current Capability of 1.0 mA to 100 mA
  • Equivalent Full-Range Temperature Coefficient of 50 ppm/ °C Typical
  • Temperature Compensated for Operation over Full Rated Operating Temperature Range
  • Low Output Noise Voltage
  • Pb-Free Packages are Available

This is the circuit of over-voltage automatic cut off switch


overvoltage protection circuit diagram

TL431A pin 

Share this

About the Author


Hi, My name is Aman bharti, I am interested in making and study of Electronics & circuit diagram. I like to share my knowledge and all ideas with people which i get from My Experiment & from different sources. I try to provide any circuit details deeply with test result as possible as. You can contact me on- Email – [email protected]

1 thought on “Over-Voltage Automatic Switch off Circuit

Leave a Reply

Your email address will not be published.