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

Comments

[Rpape871]

If I were to use MOSFETs, would it still need to be npn and pnp? This is real informative and I appreciate what you do. What I'm trying to do is create something called a radio button circuit where I can push one button to turn on an output then push another button to turn on a different output and turn the previous output off. Can this type of circuit do this? I've been searching the internet but haven't found what I need. There are a lot of 2 button latch circuits but none with 4,5 or 6 like I need. Can you point me in the right direction? It would be greatly appreciated. Thank you for any help.

[josephchrzempiec]

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?

[allserwis]

This 100 Ohm resistor is for limit current on LED, nothing to do witch switching circuit.

[HamidM38]

merci

[HamidM38]

Merci pour votre aide

[SandeepT23]

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]

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]

well explained and well executed thank you for posting

[Fearce1]

I think the circuit sim was

http://www.falstad.com/circuit/

Here is a single button circuit I found

[LukaM5]

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

[mirws]

How to use it on 3v3 system?

[neumanngregor]

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

[henkoschoeman]

how wil you build circuit using only 1 button

[BeachsideHank]

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]

Thank you sir.

[DIY Hacks and How Tos]

Nice circuit design.

[Kedar Nimbalkar]

Thanks