On Dec 19, 2:25*am, mm wrote:
On Thu, 18 Dec 2008 18:04:36 -0700, Tony Hwang
wrote:





mm wrote:
How many things do you know of where a voltmeter shows no voltage, but
the device works fine?

I bought an auto/air laptop power supply for a friend of mine, and it
was a good brand (Targus) and it's hard to imagine too high a voltage
coming from a car, but since it wasn't my computer, I thought I should
check the voltage before plugging it into his new laptop.

So, out in the car, I measured the voltage and got zero. *Even though
the light was on on the brick.
does the device have a multi-pin connector i.e. more than 2 pins?

I think that device needs to see a programming resistor to tell it
what voltage to output..

No resistor, no output.

It has nothing to do with series vs parallel regulators.

Mark