Hand sensors

[na_na_na]

Any advice or point in the right direction would be very grateful.

I am designing a storage unit that automatically opens when a hand gets near to it.
I've experimented with wiring an infra red sensor to a led circuit to also remind myself a little about wiring.
After further research I am now looking at an electromagnetic sensor (the kind used hidden inside car bumpers for reverse parking) does anyone know if these are sensitive enough to detect a hand moving towards it.

The sensor has to be hidden inside the unit.
If anyone can give the answer to this that would be great, or advice to another kind of sensor I should be looking at.

Thanks

 

[Richard Burns]

Most sensors are designed for lighting but could also power an opening circuit.
Try some of these they are a range of cupboard senors units.
Car bumper sensors, I think are normally ultrasonic and the electromagnetic ones are expensive (but would probably work but need a lot of kit and modification).

 

[tazz]

The sensors on a car bumper are ultransonic, and are configured to give a droppler effect. In security application the sensors are used to fill an area with sound, and if this pattern is interupted the alarm is activated. Most handryers, use a infra red led and receiver, pitched at 30 degs when a hand is placed near, the infra red light is reflect to the reciever. Hope this gives you some ideas

 

[Darkwood]

Get a replacement sensor board ordered for an automatic hand dryer then have some fun !!


Damn you Tazz for your speed ...you beat me to that one