cigar lighter voltage adapter

[tadpole]

Does anyone know where to get a cigar lighter voltage adapter which has several different plug fittings with different voltages - from 3v to 12v - attached. I've been told they are available.
Thanks in anticipation,
Steve

 

[David2452]

Try either Tandy or Maplins

David

 

[LadyInBed]

Car accessory’s shop
or
Radio Spares (rswww.com)
Uniross Vehicle power converter
UNI 12/MA 361-4797 £6.66
UNI 15/M 361-4804 £12.33 (+vat)

 

[Solwaycruiser]

Look in the INDEX catalogue for car cd power adaptor ( page 232 ) Only cost £7.99

 

[davidwf]

www.maplin.co.uk also do one product code UG32K

However its £9.99 plus packing.

 

[Guest]

Get a good one, and keep the packaging and receipt.

The one I bought melted after about 45 minutes use!

(and no, I wasn't overloading it, I was only running a walkman off it)

 

[Footpad]

How do they work?

I don't do electrics but when I was a kid my train set ran with a transformer
(AC 240 - AC 12) and rectifier (AC 12 - DC 12) I thought you could only transform AC and ships batteries give you DC? Explain please, in very simple terms.

 

[bedouin]

Re: How do they work?

They use a clever little device called a 'Voltage Regulator'. This can reduce the input voltage. If you want a 9V output from a 12V input then the regulator holds its output at 9V and drops the remaining 3V across its circuit. (Note - a simple regulator cannot increase the voltage.)

This is very different to transforming. A transformer can be close to 100% efficient; a simple voltage regulator works by 'wasting' the excess voltage - in the case of getting a 3V supply from a 12V source three quarters of the power is wasted, and given off as heat in the regulator, so these are only appropriate for low power circuits.

 

[Footpad]

Re: How do they work - Oh I see?

Thank you that sounds pretty convincing to me.