Topic: Cigarrette lighter power

So, cigarette lighter sockets run at 12v dc. What do i need to drop this down for the chumby to function correctly? I can get a 7805 regulator, which will step it down from anywhere up to 35v, down to +5v dc @ 1a. Im guessing thats all i need : a cigarrette adaptor, a power regulator, and a connection to the chumby. Ive got an old adaptor lying around, its just the regulator i need to figure out.


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Re: Cigarrette lighter power

The chumby will run on anything from 6V to 14V.  The power supply that comes with it generates 12V.

Re: Cigarrette lighter power

Even if Chumby will work with up to 14V you probably wouldn't want to plug it directly into a cigarette lighter socket. I've found that my car battery is already usually up around 14V and when you start the car it can spike above that.

I'd recommend a 7806 to 7812 voltage regulator with some capacitors on the input and output to smooth and filter the supply, similar to this design...

Re: Cigarrette lighter power

I found the appropriate Cigarette Lighter plug for Chumby in Digikey.

ZA5073-2.5-ND   $5.47 Ea

Datasheet is here:

The 2.5mm connector appears to be the mate for the 2.5mm receptacle on the back of the Chumbilical.
I do not have one yet... but will repost when it arrives and works.