Power toggle switch with an indicator LED

in project logs by DP | 9 comments


Meet Powah, a little power on/off toggle with an indicator LED. It uses a pair of Schmitt triggered inverters to debounce the button,  and a P-channel MOSFET to switch the power on and off. The board is designed to be plugged into a breadboard.

It is designed to mount on one end of my breadboard, so as to reduce the wear and tear caused by excessive insertions of power bus leads.  The board is approx 1 cm^2.

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  1. Nick Johnson says:

    This is a brilliant idea – why didn’t I think of this?

    List it on Tindie! I’d totally buy one. Or five. And I’m sure I’m not alone.

  2. Dolabra says:

    I like it. Sort of an over-engineered toggle switch, and I mean that as a complement :)

  3. Cabe says:

    Are the switch pins accessible? This could be useful to add to a raspberry pi’s GPIO.

  4. Brett P says:

    @Nick, with your experience on Tindie, offer to help out ! But yeah it’d be awesome to have a way to acquire some – I was kinda looking for the “buy now” button on the website but sadly no…..

  5. Destate9 says:

    I really dig this! I’d like to see a built in voltage regulator, and maybe some optional pins to measure current, but now I think I’m getting a little specific. Fantastic design though!

  6. Erik de Wit says:

    Very nice idea, but what about the copyright marking?

  7. Nick Johnson says:

    Here’s an even prettier alternative to the separate button and LED: https://www.sparkfun.com/products/10440

    I really hope he starts selling these.

  8. Paresh Mathur says:

    I like the raspberry pi idea, actually its useful for any of the boards. Apart from that, maybe add a 7805 like IC and make it a breadboard mount power supply. I would love that.

  9. Drone says:

    Interesting. I’m not a fan of stand-alone one button electronic on/off power control; better two buttons or a toggle. But that’s a topic debate for another day.

    I remembered seeing this 2004 app note from Maxim. So I’ll just toss it out as it seems somewhat topic related:

    One Button Turns Microprocessor On and Off


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