Soft Latching Power Switch ON / OFF Circuit


Introduction: Soft Latching Power Switch ON / OFF Circuit

About: Ideas Into Reality !

Simplest Soft Latching Power Push Switch ON/OFF Circuit

This soft Latching Power Switch circuit design contain only two transistor, resistors and momentary push button switches,so this is one of the cheapest way to get your work done

You can use any Transistor in this circuit, just it will need to find proper ressistance value accordingly, cheap don't always worst this circuit only consumes 1.8 Micro Amperes at off state

You can really improve this circuit by replacing mosfet's instead of transistors

Step 1: You Will Need

1. 1 kilo ohm ressistors *2
2. bc547 and bc557
3. Two push buttons
4. Protoboard

Step 2: Circuit Diagram

Follow this circuit Diagram

Step 3: Watch Full Tutorial



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15 Discussions

Merci pour votre aide

Im a very beginner to electronics.. Just a simple question.. What will happen if you hold the button for few seconds when the LED is off (or in on state also).. Will it toggles the state quickly?? If so how can we avoid that even if we holds the line for few seconds..

nice work. would this work for 36v, too or would i need other transistors?
btw. when i want to use a microcontroller to switch this thing off, i suppose, i should use a third transistor to switch the npn base to ground? (especially when using 36V)..

well explained and well executed thank you for posting

no, it was everycircuit the free version has a limit of 5 components though, to it's pretty useless.


1 year ago

How to use it on 3v3 system?

Helloin your specs you have the 2 transistors and 2 of the 1k resistors But in your Circuit Diagram It haves all that and a 100ohms resistor. What is that for?

Frend, what program do you use for the circuit simulation, its amazing ?

how wil you build circuit using only 1 button

You have fully documented your build, and shown the theory of operation in a clear, understandable and intelligent manner, as well as demonstrating possible alternative uses; this is the way of a good educator, well done!

1 reply