Power button, power LED, and mini project.

Power button for lunch box:

Isn't it shiny!

It uses the 12v line to power the ring LED. I had an idea that instead of drilling another hole in the case of the flimsy lunch box tin, I should just make the power LED flash off when there is HDD activity. However the first problem is how to power off a LED when another line goes high? Looks like a Not logic gate (inverter) would solve that one. 2nd problem is that the HDD activity LED would normally be 5v and my shiny power LED is 12v. So something called a Darlington pair should hopefully solve this problem. So putting the two concepts together I have arrived at this circuit.


Any comments on improvements? Is the resistor on the ground too much? I though that it may protect the 5v rails from the 12v rail, as the 5v rail is signals only, and the 12v rail is the one with the actual load.

Power - Done!

Closed the case, and ran Memtest86 for a bit.





Looked good, except the case did get a bit toasty. Don't think that an HDD will like that heat, so going to have to look at what I can do about ventilation or cooling.

PSU Install

The PSU is a DC to DC board, powered by an external laptop style 12V power brick.
So found that the best place for the PSU was glued to the lid. Note the insulating cardboard. The glue used is epoxy resin, so it sets rock hard and adds to the insulating quality's needed.

Motherboard installed

Still need to glue the rest of the pieces in, but the motherboard is snug as a bug in a rug.