Pololu Robotics & Electronics
My account Comments or questions? About Pololu Contact Ordering information Distributors

Mini Pushbutton Power Switch #2808


I am building a cnc router and want to put all the electronics in a PC case and use the pc power button to power on the 24 pin breakout board. I wanted to use a pc power supply to power some of the electronics and a relay to turn on the other power supplies. I have very limited knowledge of electronics and after looking around I found this sparkfun benchtop power board kit


The problem I am having is that it uses a SPDT switch and I want to use the pc case switch. Then I found this board and thought I could get it to work.

It didn’t work and I am not sure if I wired it wrong or to much voltage so I am here asking for help.



From the SparkFun Benchtop Power Board Kit’s schematic, it looks like the switch’s common pin on that board is tied to the PS_ON pin of the ATX connector. (You can find that schematic under the “Documents” heading on its product page.) The PS_ON pin is an active low control pin, meaning it needs to connect to ground for the power supply unit (PSU) to turn on, so the mini pushbutton power switch would not be appropriate for turning on your PSU.

You might be able to use the pushbutton power switch to turn on and off power to other devices in your system with a push button, but from your description it sounds like you want the whole router to turn on with one button.

- Amanda


Thanks for your reply. Is it possible to make my own latching circuit with momentary switch that works the right way? I know almost nothing about electronics and am not sure how to do it but if it was posible and I could find an example to follow it would be fun to try.


Sure; it might be possible to design your own circuit for your system, and you might be able to find some tutorial, or more likely, schematics of a circuit turning a momentary pushbutton into a latching power switch. Probably the easiest solution (and most practical) would be to find a latching pushbutton like this one instead of a momentary pushbutton similar to what typical computers use.

- Amanda