mystery power adapter, how to measure output?

[Matt Kime]

i have a kensington universal power adapter with several plugs. the
different plugs supply different voltage..how do i measure the voltage
without plugging the power supply into an appropriate device?

thanks,
matt

[Ronald "Monty" Montemayor]

voltmeter?

[Matthew Sparks]

You could plug it in and measure each plug with a voltmeter or
you could go here
http://us.kensington.com/html/1458.html
find the technical specs on the model you have and look it up

Matt Sparks

[Ryan Micallef]

Did you have an inappropriate device in mind?

[Matt Kime]

I was under the impression that you can only measure voltage under load.

[michaeldepasquale]

voltage is a constant thing and can be measured when ever feel like
it amps and watts are different thing

[Stephen DeLay Jr.]

The voltmeter would act as the load

Sent from my iPod

[Rob Graham]

current usually varies the most with load.  On power supplies, it's usually the voltage that's regulated, not the current.

---

From: Matt Kime <matt...@gmail.com>
To: nycresistormi...@googlegroups.com
Sent: Mon, October 26, 2009 6:33:23 PM
Subject: [NYCR:Microcontrollers] Re: mystery power adapter, how to measure output?

[Ben Combee]

On Mon, Oct 26, 2009 at 5:33 PM, Matt Kime <matt...@gmail.com> wrote:
>
> I was under the impression that you can only measure voltage under load.

Cheap non-switching power supplies will vary their voltage depending
on the load. Usually systems using those kind of supplies have an
internal power regulator like a 7805 that ensures that the voltage is
constant.

[Dan Lavin]

Use a resistor as a dummy load and measure the voltage with a meter.
Estimate the resistance by looking at the requirements for the device
you want to use it with. You do not have to be particularly close. If
in doubt, try for a 100ma load, i.e. 100 ohms for a 10volt supply.
Don't worry about wattage; you are only going to apply power for a few
seconds.

[Matt Kime]

I stand corrected, and better yet, educated.

AND

The power supply works for my needs!

thanks!

[Ronald "Monty" Montemayor]

 

dont worry, these are not inborn talent.

 

I licked a 9v battery once, because I didn't ask.

[michaeldepasquale]

i was going to say lick it and have some count how long your out for in seconds and thats the aprox voltage.....

just kidding 

[Rob Graham]

Are you not supposed to do that?  I still lick a 9v to see if it's dead or not.

---

From: "Ronald "Monty" Montemayor" <rbmont...@gmail.com>
To: nycresistormi...@googlegroups.com
Sent: Tue, October 27, 2009 9:40:05 AM

Subject: [NYCR:Microcontrollers] Re: mystery power adapter, how to measure output?

[Ronald "Monty" Montemayor]

 

my tongue is very sensitive. i guess its ok for a regular batt.

 

but, how about some lipo battery?