Introduction: Soft Latching Power Switch ON / OFF Circuit

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


SandeepT23 made it! (author)2017-07-06

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..

TecDroiD made it! (author)2017-04-24

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)..

Doc Darkness made it! (author)2017-03-19

well explained and well executed thank you for posting

Fearce1 made it! (author)2015-11-27

I think the circuit sim was

Here is a single button circuit I found

LukaM5 made it! (author)LukaM52017-03-11

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

mirws made it! (author)2017-02-05

How to use it on 3v3 system?

josephchrzempiec made it! (author)2015-12-06

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?

neumanngregor made it! (author)2015-09-10

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

Volthaus Electronics Laboratory made it! (author)2015-06-30

This is a very fascinating circuit. I have tried some slightly different configurations of your circuit and I am able to turn on and off a circuit using only one button on the Infrared remote controller. I was also wondering what were the second pair of transistors you tried in your circuit in the video? I could not catch exactly what you were saying. Also of use is the impedance change on the output of your circuit in my variation. Now to see how using mosfets work. Thank you for posting this, it is very fun!

henkoschoeman made it! (author)2015-06-26

how wil you build circuit using only 1 button

BeachsideHank made it! (author)2015-06-21

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!

Kedar Nimbalkar made it! (author)Kedar Nimbalkar2015-06-21

Thank you sir.

DIY Hacks and How Tos made it! (author)2015-06-21

Nice circuit design.

Kedar Nimbalkar made it! (author)Kedar Nimbalkar2015-06-21


About This Instructable




Bio: Ideas Into Reality !
More by Kedar Nimbalkar:DIY Wireless Charging for Your Gaming Mouse ! - Goodbye Batteries Make Coca Cola Soda Fountain Dispenser Machine at Your Home Fridge !How To Make EMP Gun !
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