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Simple Relay Question - Will this work as intended?

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Theytonn

New Member
I would like to say Hi to everyone and thanks for taking the time to read this.

Here it goes-

I'm planning a custom PC case, one which the power on and power off are two different switches. I want the same switch to do both, so I drew this little thing -->



When the PC is powered off, the switch is the Mobo's power switch. When the switch is triggered, PC turns on, PSU goes high, energizing the relay, making the switch my "keyboard" F2 key (which is the hotkey for system shutdown). When the system shuts down, PSU goes dead, reverting the switch back to being the Mobo power switch.

In my mind, this should work as expected but then again I am no electronics guru. I have read that relays can make current surges/spikes and what-nots when switched. Do I have to worry about that? Do I have to worry about the relay restarting the PC when it switches off? If so, what can I do to solve these problems or any other problem you guys can see with this?

This is my first time working with relays so I just wanna make sure this will work before I blow the mobo header or keyboard.

Thanks for any replies.
T.
 
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Hero999

Banned
I don't see any problem with that.

Soldering to the keyboard might be difficult though.
 

Theytonn

New Member
I don't see any problem with that.
Thought so, but I had to be sure. I try to make sure lack of research isn't the reason behind a 130$ mistake!!

You'll have to isolate the F2 key from the keyboard scanning matrix.
Ya, that was a fun job to do. I have isolated all 'F' keys and wired the keyboard PCB to a stripboard. Took me a while to fallow all the circuits on both keyboard membranes to find out which contacts were needed to give me the needed keystrokes. If I may add, if you ever need to do this, photocopy the membranes, it makes the job way easier!

Thanks for the replies.
 

wilykat

Member
Depending on the OS, you could already set it to use power button as power off. In Windows XP and Vista for example, in Power control panel you could set the power button to power off instead of sleep (as it is default with some OS) I have mine to "do nothing" because my cat loves the pretty blinking button and have inadverantly shut my PC down often. :mad:

Without knowing what OS you are using I can't tell if you can do it without the above relay rig.
 

Theytonn

New Member
Without knowing what OS you are using I can't tell if you can do it without the above relay rig.
I am using XP, but the PC will get booted into a kiosk mode, removing any possibility of using any of XP's shutdown functions. I have to use the kiosk program's shutdown command, which I scripted to the F2 key. Thus my dilemma :D
 
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