Electronic Multimeter help required

sigma · 12 May 2010 at 23:54

Edit : already answered.

littledave · 12 May 2010 at 23:55

If you set the mulitmeter to the 200V scale, the 2nd position to the right, also because its AC I would expect a reading of 9-11V which ever way you connect the leads

Assuming the PSU is working they normally output a higher voltage until a load is applied, this is what several people have said about the reading being rubbish.

But as an electrician this is the correct way of measuring voltage, the mutimeter has a internal load which what it uses to work out the voltage.

D.Roberts · 12 May 2010 at 23:59

Hi why would you get -11?

I understand why you should get 9 or -9 depending on how you connect it but why -11?.

Please don't get me wrong i am not questioning you as you have just said you is a sparky im actually interested in the answer as I don't know.

Hotwired · 13 May 2010 at 00:06

9 to 11 volts is what I interpreted 9-11v as.

and

they normally output a higher voltage until a load is applied

is possibly the other answer?

D.Roberts · 13 May 2010 at 00:09

ah its just that he says "which ever way you wire the leads" nm im being silly its late etc well for me any ways

SexyGreyFox · 13 May 2010 at 00:09

neodude said:
It needs to be turned to the right. Either the 600 or 200 scale. 200 would be the obvious choice to pick up 9V but at that scale it might not be sensitive enough.

littledave said:
If you set the mulitmeter to the 200V scale, the 2nd position to the right, also because its AC I would expect a reading of 9-11V which ever way you connect the leads

Hurrah - 10.6
Thanks for that.
Now I know how to test power supplies.

RobH · 13 May 2010 at 00:15

The V with a tilde (V~) is volts AC which you need to use to measure the power supply output assuming it is an AC-AC adapter (compared to things like phone chargers which are AC-DC). It's also worth mentioning that it's very easy to take out the internal fuses on cheap multimeters when measuring current, the meter will still work but you won't be able to measure current.

littledave · 13 May 2010 at 00:21

Glad to see you figured it out.

Dont want to confuse you but for future use there are normally 2 types of power supplies.

Regulated and Unregulated, this refers to the power supply control circuit, the more expensive ones are regulated. This is where the power supply controls the voltage at a specfic constant level.

With an Unregulated PSU you may see spikes or drops in the voltage measured