[dorkbotnyc-blabber] voltage differences: powering a 9-volt thing with a wall socket powered device

[douglas repetto]

It's probably just a relay that's switching the 110v wall current on and 
off when it detects motion. Check it with a voltage meter to be sure! If 
it is, then you can simply plug in a 9v DC power transformer ("wall 
wart", available at Radio Shack). That way when the sensor turns to 
power on and off it'll be just like you plugging and unplugging the wall 
wart from the wall.

What does the physical connection between the sensor and the lights look 
like? If it's a 2 or 3 prong jack then just plug in the 9v DC 
transformer as you would plug it into the wall. If it's directly wired 
to the lights then you'll need to get a bit creative -- but be careful! 
Wire it up with the sensor UNPLUGGED and make sure you understand what 
you've done before you turn it on. You're dealing with 120v AC wall 
current, and if you make a mistake you can get hurt! Maybe best to ask 
someone who's done it before.

best,
douglas

Jascha Narveson wrote:
> 
> Hello, Dorkbot -
> 
> Quick question:  i've got a 9-volt battery powered circuit which I want 
> to power with an off-the-shelf 
> turn-the-lights-on-when-the-bad-guy-gets-near-your-house motion sensor.  
> The sensor runs off normal 110 AC power, and I'm not sure what kind of 
> power it's feeding to the light bulbs, but it's higher than 9 volts.  Is 
> there an easy way to change the output of the sensor to safely power the 
> circuit?
> 
> thanks,
> 
> jascha
> ........................................................................
> .........dorkbot: people doing strange things with electricity..........
> ..........................http://dorkbot.org............................
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