newbie question

Jul 21, 2006 4 Replies
V

Hi guys,



I wonder if anyone can help me with this simple problem I have as art of my school project..



I am trying to turn an electrical current on and off down a wire via a wireless signal on a key fob.



The cable is connected to a light. All I need to do is switch it on and off -remotely. Yes, I have seen remote light dimmers, but all I need to do is switch the light on and off (not dim) and make the circuit as cheap and easy as possible.



Can anyone tell me what the simple circuit diagram should look like, and what components need to be on the pcb etc?



Plus if anyone can - what the circuit in the key fob should look like.


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J

was: newbie question

voodoochile MULTI-POSTED:

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*-*-*-*-*-*-*-*-appear+*-proper-answer-*-*-*-given+much-easier-*-*-*-*-what's-going-on+*-frowned-on+*-correcting+*-polite-*-mention-*-*-*-*-*-*-*+Just-because-*-*-*-*-*-*-*-*-does-not-mean-*-*-*-*-*-*+*-Followup-To-*+*-*-*-too-lazy-*-*-*-*-*-appropriate-*+*-*-_perfect_-*-*-*-*+*-*-*-*-two-groups-*-*-aren't-*-different

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S

Outfits like Radio Shack probably have kits just for that.

Bill

-- Ferme le Bush

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P

OK. Wireless basically means radio, optical or acoustic.

Acoustic is pretty easy. Your fob would have an oscillator circuit connected to an ultrasonic transducer. The receiver is another ultrasonic transducer with amplifier, followed by a divide by two counter with one output driving a relay.

Optical is much the same, except you would use LEDs and optical sensors instead. You can get optical sensors with amplifiers built-in - with outputs almost ready to be used to clock the divide by two circuit.

Wireless is a bit trickier as licencing may be involved and aerial design can be problematic. Best avoided unless you are allowed to use pre-built transmitters and receivers. eg, taken from a toy rc car, perhaps?

Cheapest probably means optical.

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B

I got one of these down at Home Depot. Works great.

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