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

[Jascha Narveson]

Ah ha!  I didn't know screw-in outlets existed - these combined with  
a normal 9v-dc adaptor makes the whole thing suddenly pretty easy.

thanks, all,

jascha




On Dec 21, 2007, at 9:52 AM, jeb boniakowski wrote:


> If its direct-wired to the lights, you could just unscrew the bulbs  
> and put in one of those adapters that converts a normal  
> incandescant bulb socket into a power outlet.  that would probably  
> be the easiest thing.
>
> (oddly, my old roommate did a proj that involved doing this exact  
> thing last year, and as you would expect there's some simple  
> circuit in there that flips a relay to power the lights.  For a  
> variety of reasons, though, he said once you start taking it apart  
> its actually much easier to just build a new circuit using the  
> sensing element then to adapt the one in the box.)
>
> On Dec 21, 2007 9:47 AM, douglas repetto  
> <douglas at music.columbia.edu> wrote:
>
> 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............................
> > .................................................................... 
> ....
>
> --
> ............................................... http://artbots.org
> .....douglas.....irving........................ http://dorkbot.org
> .......................... http://music.columbia.edu/cmc/music-dsp
> .......... repetto............. http://music.columbia.edu/organism
> ............................... http://music.columbia.edu/~douglas
>
> ...................................................................... 
> ..
> .........dorkbot: people doing strange things with  
> electricity..........
> ..........................http:// 
> dorkbot.org............................
> ...................................................................... 
> ..
>
> ...................................................................... 
> ..
> .........dorkbot: people doing strange things with  
> electricity..........
> ..........................http:// 
> dorkbot.org............................
> ...................................................................... 
> ..

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://music.columbia.edu/pipermail/dorkbotnyc-blabber/attachments/20071221/26fa2ce3/attachment-0001.html