Latch-up circuit using 555 and opto-coupler
Here’s a simple latch-up circuit using 555 timer and opto-coupler MCT2E. You can also use PC817 in place of MCT2E. The NE555 timer is configured in astable mode.The components are selected in such a way that the frequency output of the astable circuit lies within the audio range. Opto-coupler, MCT2E is is used for latching…