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zachj
10-26-02, 09:55 PM
There is a Power Mac Dual G4 800MHZ with 17 in. LCD in my school's computer lab. The coolest part of the whole thing is the screen. I want one, but I digress.

My question is to do with the extremely cool power button on the display. There is not an actual button there, you just tap it and miraculously, the thing turns on or off. I was wondering how that works and where I could get my hands on that contraption for use on my computer. I assume it works via motion activation or light sensors or something, but I don't know. If someone does, by all means, inform me, please.

Thanks

Z

BaldHeadedDork
10-26-02, 10:37 PM
Its probably a basic thermal sensor. This is a sensor, mounted behind plastic, that detects the presence of a heat source and flips the switch.

We have hundreds of them on machines at the factory where I work. They're used as safety switches to ensure the machine operators do not have their hands in harms way before the work operation will start.

But the ones we use are about 1.5 inches cubed, with a recessed area in the top for your finger. If you want to use something industrial like this, you can get them at any industrial supply warehouse like Grainger.

For something slimmer like in the Mac display, you'll have to do some digging. Good luck!


BHD

Captain Slug
10-26-02, 11:48 PM
Originally posted by BaldHeadedDork
Its probably a basic thermal sensor. This is a sensor, mounted behind plastic, that detects the presence of a heat source and flips the switch.

It's more likely to be a capacitive touch switch which "eats" the static noise that comes off your body when you touch a metal sensing plate. These require almost no power to operate and can be very small.
I've seen widely available kits online for $6.50 to $12 depending on how complex you want it to be.
They also look alot coolers since they could be wired to any capacitive surface such as a rivet head, screw, or bolt.