I've been meaning to build a shutoff switch for my machine in case if the pump ever fails, my machine will automatically shut down after (5 seconds).
My problem being that I used to dabble with electonics, but this was about 10 years ago as a hobby and since then I've forgotten most of the fundamentals and I cannot seem to find any of my books.
I will
not run extra software to do this. Electonically, this is very simple, but I forgot how to make a switch using transistors.
Heres what I'm wanting to accomplish...
I have my watercooling system, and whenever it detects that the pump has stopped, a buzzer emmits a low voltage tone (approx 1 volt). Oscillation of probably 3-4KHz (no scope to find out actual tone).
Whenever the alarm is triggered that my pump has stopped, I want my switch to wait approximately 5 seconds, then close the "power swtich" circuit to make the computer think the power switch has been pressed and it shuts down...
Heres what I have in mind for the connections...
Motherboard power switch header is split into 2 headers. One going to the front case switch, the other going to the electonic switch.
The buzzer on the pump sensor is removed, and the cables are run to the electonic switch. Another buzzer can be manually made. I know how to make them...
The electonic switch, when it detects the signal coming from the buzzer cable, the transistor waits 5 seconds (use of a capacitor & resisor), then closes the circut that is attached to the 2nd power header (grounding it), thus shutting down the machine as if the power button was pressed.
Does anyone know of a place where I can get some schematics, or an electonic forum where I could pose such question so I can build it?
Thanks in advance...
Linear Mode
