IR Computer Power Switch

[EricH]

Hey, I'm new here and any help would be greatly appreciated. I'm going to be doing a few projects this summer, so I'll definitly be around.

So I need help on where to start. I'm going to be making a computer switch controlled by IR. How it works to me doesn't matter. It could be a small solenoid pressing the power button that already is in place or it could be an actual open/closed circuit with the IR. What do you guys think is the best to do this?

 

[RadioRon]

The IR transmitter and receiver are the most fun part as there are so many transceiver ICs to choose from these days. Once you get your ON/OFF output from the receiver, you might as well just use a solid state relay to do the switching. There are many with 5V input that switch 120V mains.

On second thought, aren't most computers using soft ON/OFF switching these days, in which case just switching the line on/off won't help. I guess you need a simple relay in parallel with the pushbutton on the front of your PC. Relays may be old fashioned, but at least they are isolated so easy to patch in to an existing circuit.

 

[Hero999]

Sorry if I'm prejudging you but that language you've used indicates that you don't have much experiance, what's the most complecated project you've built before?

Have you actually designed anything rather than building other people's designs.

I don't mean to offend but to gauge your level of understanding as it'll make it easier for myself and others to help you.

 

[EricH]

I've built a few things from scratch without a schematic. Mostly, however, they were simple. I've built many things following others schematic's though. Really all I am looking for is a schematic once you've told me what design would be the best for this project. I've used relays before, but I'm not exactly sure how I would in this case. The only idea I can fathom is a solenoid actually pressing the button in place. So you are right to assume I'm not very experienced.

 

[Hero999]

I have a circuit in a magazine somewhere that'll do this, it was origionally designed for ultrasound but it can easilly be converted to IR. I can't post it now because I don't have a scanner, so you'll have to wait until I get back to work (providing I can find the magazine that is).

 

[EricH]

Thank you.

 

[Hero999]

Oh well for now I'll breifly describe it.

Transmitter
Simply a NE555 and piezo ultrasonic transducer, running at 40kHz in series with a push-button switch - this was powered from a 9V battery.

Receiver:
A piezo transducer connected to a pre-amp going to a LM567 tone decoder set at 40kHz, a JK flip-flop is used as a latch to turn a 240V relay on and off - this was powered from a simple transformer and rectifier.

It was easy to use, press the push button on the transmitter once to turn off, then again to turn on again - just like the pull cord light switch in the bathroom.

 

[EricH]

Got ya, and I could even Ultrasonic instead of IR, the method it does it by doesn't concern me that much. Easier to just stick with the schematic.