In this article, I am sharing a simple DC short circuit protection circuit. This circuit is very useful in various situations, such as if you are going to build a 12V light circuit or voltage sensitive circuit. This will protect the short circuit and further damage of the connected Lights or device.
DC Short Circuit Protection Circuit
This is a simple DC short circuit protection circuit built with a few electronic components. The IRFZ44 MOSFET and an 817 optocoupler safeguard the output from excessive current and a short circuit. The 12V DC input powers the circuit.
Components Required to Build Short Circuit Protection Circuit
| Component | Value/Part Number |
|---|---|
| MOSFET | IRFZ44 |
| Optocoupler | PC817 |
| Resistor | 100KΩ |
| Resistor | 1KΩ (×3) |
| LED | Red LED |
| Push Button | Momentary Switch |
| Connector | 2-Pin Terminal Block (Input: GND, 12V) |
| Connector | 2-Pin Terminal Block (Output) |
Working and Explanation
The MOSFET acting as the main switching component it will turn on and off. Under normal conditions, the MOSFET remains ON and it allowing current to flow through the output terminal.
A current sensing mechanism is implemented using the 817 optocoupler and resistors. It will monitor the current flow at the output. If a short circuit occurs an excessive current triggers the 817 optocoupler and triggers the MOSFET.
This will turn off power to the output and protect the connected devices. The circuit includes a manual reset button which must be pressed to reactivate the MOSFET after a short circuit event occurred. Additionally an LED indicator provides a visual status update. Signaling whether the circuit is operational or in short circuit.
When the short circuit happens the LED turns on. This protection system is ideal for 12V battery powered devices, DC power supplies, and automotive applications, preventing damage due to unintended short circuits.
Also Check: Dc Bench Power Supply
