• From: United Kingdom
  • Registered: 2006-08-28
  • Posts: 245

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.

thanks.

need upload space for the forums or a chumby blog? right here then
http://www.nophus.com/useru
username is chumby
password is chumby

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  • Duane
  • Duane
  • Blue Octy
  • Offline
  • From: San Diego, CA
  • Registered: 2006-08-24
  • Posts: 8,197

Re: Cigarrette lighter power

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

Duane's Website

  • Registered: 2006-12-27
  • Posts: 4

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...

http://www.seetron.com/an_vpwr1.htm

  • Registered: 2007-02-20
  • Posts: 26

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:
http://www.12v-parts.com/za5073-2.5.pdf

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.

Bruce