SparkFun Forums

[TofuNinja]

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

https://www.sparkfun.com/products/12867

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.

https://www.pololu.com/product/2808

It didn't work so I am here asking for help. Here are some pics of the board I have and of how I wired it.

https://i.imgur.com/PGe4YWT.jpg

https://i.imgur.com/hd2beXh.jpg

https://i.imgur.com/Z6jmoUl.jpg

https://i.imgur.com/pDFl5O5.jpg

https://i.imgur.com/1a23eWU.jpg

[n1ist]

That module switches the hot lead; the power supply board needs a connection to ground to turn on. While I would probably solve this problem by changing the switch on the PC case to a toggle switch (SPST is fine; they are only using the NO contact on the switch), you could follow the Pololu board you used with a FET or relay to allow it to switch the POWER_ON pin to ground.

/mike

[TofuNinja]

you could follow the Pololu board you used with a FET or relay to allow it to switch the POWER_ON pin to ground.

/mike

Thanks for the reply. I would like to try your suggestion of using a FET or relay. I know almost nothing about electronics and am not sure how to do it. Could you tell me how I need to wire it up.

[TofuNinja]

is it possible to make my own latching circuit with momentary switch that works the right way?

[TofuNinja]

Would something like this work?

http://todbot.com/blog/2010/01/02/momen ... using-555/