Power toggle switch with an indicator LED

Posted on Thursday, February 7th, 2013 in project logs by DP


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.

This entry was posted on Thursday, February 7th, 2013 at 9:00 pm and is filed under project logs. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

9 Responses to “Power toggle switch with an indicator LED”

  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:

    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

Leave a Reply

Notify me of followup comments via e-mail. You can also subscribe without commenting.

Recent Comments

  • KH: After reading all the comments, I have questions: Does this mean STM32 and AVR boards/parts from dodgy online sellers are suspect? What are your opinions?...
  • Sjaak: They are available with more flash then their ST counterparts which makes them more interesting. You don't have to port the code, but use another...
  • Sjaak: I dunno if you can 'license' register definitions, but I'm not a lawyer. Since the chip is available since 2015 and I haven't heard of...
  • Sjaak: They can be found on taobao or the Chinese markets in Shenzhen.
  • KH: I've been a really good boy, I only buy MCU parts from RS and Farnell. :-)