Super easy minimal latching switch

For my power supply I wanted a momentary latching switch for controlling the output function to be on or off. I’ve tried a few circuits here and there and just didn’t fit the bill. Then it hit me, what about a Thyristor? Well sure enough it does the job and with only three resistors and two switches to control on and off. Granted it would be nice to have a single switch to control it but the nice feature with two switches is I can hold in the OFF button to make the circuit active momentarily.

I found a schematic with google images but it was a bit unstable so I tweaked it. I use a 12volt source to power it and added a extra 1K resistor the stabilize the current.


The 1K isn’t really needed but for my needs it does since I have a N-Channel Mosfet working as a high side switch and a LED for output status.

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