Trying to measure current with a multimeter - what on earth am I doing wrong?

Thread Starter

Themusicman

Joined Apr 2, 2017
48
Hey all

I feel such a numpty for asking this, but for the life of me I can't seem to read current!

To test, I have a simple LED circuit: 9V battery, string of LED's.

1. Set multimeter to DC Current
2. Insert multimeter between ground and LED's

Nothing reads on meter. Nada!

Tried two meters, so obviously have missed my meds this morning or am a few sandwiches short of a picnic. Someone have a laff and put me out of my misery please. What am I not doing here?

Thanks....
 

wayneh

Joined Sep 9, 2010
16,399
Are the LEDs lighting while you get no reading? It's possible that the meter wants the probe inserted in a different socket on the meter. Look for that. It's also possible that the meter itself drops just enough voltage to fall below the minimum forward voltage required to light your string. That may be a long shot but it could happen.
 

Thread Starter

Themusicman

Joined Apr 2, 2017
48
Hi both

No, the LED's are not lighting when I connect as described, though they work when connected directly without the multimeter.

I've put the probe in the 'A' socket (there's two of those, 2A and 10A) and I have inserted the Black into common and the red into 2A, with the multimeter on DC 2 Amps scale.

This is weird!
 

Externet

Joined Nov 29, 2005
1,529
Check the fuse inside your multimeter; probably by the battery door. Is the brandy to celebrate it reads now or to drown your frustration ?
 

Thread Starter

Themusicman

Joined Apr 2, 2017
48
Check the fuse inside your multimeter; probably by the battery door. Is the brandy to celebrate it reads now or to drown your frustration ?
Definitely to drown frustration! I feel such a twit asking this, but I just can't read current! Two meters too!

Is the fuse a dedicated Amp reading fuse as the meter reads AC/DC V and Ω fine! I will check though!
 

Externet

Joined Nov 29, 2005
1,529
If fuse tests good, next make sure the plug is fully inserted; some multimeters have a switch deep in the jack to enable current measurement. If you are using non-original probes, that may do it too.
 

Thread Starter

Themusicman

Joined Apr 2, 2017
48
If fuse tests good, next make sure the plug is fully inserted; some multimeters have a switch deep in the jack to enable current measurement. If you are using non-original probes, that may do it too.
Well would you Adam and Eve it!!?? Darned fuse blown on multimeter #1...!!

Not sure of multimeter #2 as can't see a fuse in that one, only battery under cover.

Thanks for the pointers sir! Top man!
 

Externet

Joined Nov 29, 2005
1,529
Time for a Bourbon... works better than brandy.
Happens in the best of families. At some point current measurement was attempted with selector in 'V'.
Replace fuse with same rating or something else may blow at next goof.
 

Thread Starter

Themusicman

Joined Apr 2, 2017
48
Time for a Bourbon... works better than brandy.
Happens in the best of families. At some point current measurement was attempted with selector in 'V'.
Aha...!!! that's how the fuse blew then yes? I can't recall doing so, but also can't deny I may have inadvertently done that.

And darned it, I wanted to measure the current draw to my currently not working RS rechargeable soldering iron (excuse the pun!!). Also, it's a Friday, it's only 00:48 - Fridays are meant for Arduinos, electronics and well, stuff :)
 

Thread Starter

Themusicman

Joined Apr 2, 2017
48
That is the correct way to tell time, not as 12:48 AM as they say here...
Wine it is!! I don't have to get up in the morning!

Oh, spotted you're mideast... would that be the St Louis area? (excuse my limited US geographical knowledge). I've been to St Louis a few times, and have also been fortunate enough to have visited many areas in the US several times.
 
It doesn't take to much to find out the general area where he lives. just a click on his profile image, and you can find out that he is in the mideast. :confused:now to find out the definition of mideast.
A.H.W.
 

Thread Starter

Themusicman

Joined Apr 2, 2017
48
I hope our language usage didn't corrupt your English too much.:D
Haha.... mideast is HUGE!!!! Remember, I am from little Welsh Wales :)

I've loved every visit to the US. (Well, coming through customs as a non US citizen at LAX is not the most pleasant experience - but after you get out it's a different world!!)

Best trip was on a free weekend during a 3 week business trip. Offices were in San Bernadino, so on my free weekend I left mid-afternoon Friday and drove to Palm Springs. Next morning drove to Baker (is it Baker? where Julia Roberts was the solilcitors buddy in that film), through High Desert, to Canyon, then to the awesome Death Valley, then back tro Palm Springs. Sunday was a day by the pool in the heat :)
 

Externet

Joined Nov 29, 2005
1,529
Mideast U.S. is between Eastern U.S. and Midwest U.S. Or if you prefer, as U.S. has 4 main time zones, match each to Eastern, mideast, midwest, Western.
If that is still hard, settle with the land of Bourbon. -Kentucky-
 

MrChips

Joined Oct 2, 2009
21,666
Blown fuse in meter. Happens all the time when dummy tries to measure voltage with the meter in current mode.
An "ideal" meter set to measure current has zero resistance. Hence that is a short circuit across any voltage source.
 
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