How to Make Protection Circuit | Short-Circuit & Current Limiter | Step By Step

In this video, I build a protection circuit step by step:

1.Short-circuit protection – starting with a simple relay and push button that cuts off the load when a short occurs.

2.Current sensing – adding a shunt resistor to detect overload by measuring voltage drop.

3.Comparator stage – using the LM358 op-amp to compare the shunt voltage with a reference, turning it into a current limiter.

4.Logic correction – adding an inverter stage to make the control signal work properly with the relay.

5.Stability improvement – applying positive feedback (hysteresis) so the relay doesn’t chatter near the threshold.

6.Reset function & protection – adding a reset button and a diode across the relay coil to protect the transistor.

7.Final test – checking the circuit under normal load, overload, and short-circuit conditions.

So, starting from a simple relay to replace a fuse, step by step we’ve built a complete protection circuit: short-circuit cut-off, current limiting under overload, stable operation, and a safe reset function. If you found this video helpful, don’t forget to hit like and subscribe to follow my upcoming projects!