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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders.

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Old 13th Feb 2021, 10:40 pm   #1
erasmo0
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Default DMM

Hello people,is the connection of the leads to measure the mA correct? but if I should measure the current A and leave the red lead in the first output on the left and the black in the last one on the right, what can happen?
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Old 13th Feb 2021, 11:09 pm   #2
erasmo0
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Default Re: DMM

itís photo of my tester
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Old 14th Feb 2021, 12:03 am   #3
Herald1360
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Default Re: DMM

With a bit of luck, nothing. It just won't work. The V♤ socket on the left should have a high enough resistance to the mA or 10A for nothing much to happen.

Worst case, you'll need to buy another cheap meter!

Note: ♤ symbol.... can't do a proper omega symbol on my tablet
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Old 14th Feb 2021, 7:16 pm   #4
Ed_Dinning
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Default Re: DMM

Hi Just a note to say beware when measuring current

To measure current you must "break into" the circuit (insert the meter into one of the wires.
Please do not connect across the wires (as when measuring voltage) as that is a good way to destroy the meter.
My apologies if you already know this, but from tales of destroyed meters some people may not.

Ed
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Old 14th Feb 2021, 9:38 pm   #5
erasmo0
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Default Re: DMM

excellent, clarification ... I had forgotten to remove the red cable from the first output and the black instead of connecting it to common, I had connected it to the last output that is to ampere, but the two test leads I had put them in series with the positive a car radio...oh yes,i know it's dangerous to measure current with knob in volt/ohm...many ths for info
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Old 14th Feb 2021, 10:19 pm   #6
usradcoll1
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Default Re: DMM

Quote:
Originally Posted by Ed_Dinning View Post
Hi Just a note to say beware when measuring current

To measure current you must "break into" the circuit (insert the meter into one of the wires.
Please do not connect across the wires (as when measuring voltage) as that is a good way to destroy the meter.
My apologies if you already know this, but from tales of destroyed meters some people may not.

Ed
One of my neighbors near my workshop mentioned that when he used his digital meter, he didn't get any reading and the test leads got extremely hot.
I inquired how he had the leads connected and he showed what input jacks he used. The leads were connected to the common and the 20 amp current jacks. I explained the proper way. It was a meter that was included free with any purchase at the import tool store.
Dave, USradcoll1
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Old 15th Feb 2021, 12:53 am   #7
Julesomega
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Default Re: DMM

Quote:
Originally Posted by erasmo0 View Post
...oh yes,i know it's dangerous to measure current with knob in volt/ohm...
Careful, that should be the other way round
See again post #4
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Old 17th Feb 2021, 8:46 pm   #8
jamesinnewcastl
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Default Re: DMM

Hi

When I was about 10 and got my first multimeter for Christmas I thought I would measure the current output of my uncles PSU. So set the meter to Amps and put the leads across the terminals!

It did take a good long while to work out why the fuse blew!


James
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Old 18th Feb 2021, 7:37 am   #9
Diabolical Artificer
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Default Re: DMM

Quote:
When I was about 10 and got my first multimeter for Christmas I thought I would measure the current output of my uncles PSU
It was a lorry battery with me.
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Old 18th Feb 2021, 9:19 am   #10
Denis G4DWC
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As an apprentice, the Boss had loaned me the Workshop AVO 7 to do some transformer measurements for a project. My friend Bob, (Yes really!) inadvertently tried to measure the internal resistance of an 8Amp Variac whilst it was switched on. The AVO pointer hit the end stop PDQ, bent it and we spent the rest of the evening with the AVO in bits trying to straighten it!

Lesson learned to always engage brain and make absolutely sure you know exactly what you are intending to measure before applying the test probes.

Denis
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Old 18th Feb 2021, 11:04 am   #11
Kala_12
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Default Re: DMM

Quote:
.... always engage brain and make absolutely sure you know exactly what you are intending to measure before applying the test probes.
Seconded.
Some years ago I was checking an amplifier's transformer for continuity. When that was OK, I switched on to measure the a/c out (and mains in) of the said transformer. Yes, the step I missed was to change the multimeter to 300v a/c before applying the probes. Oh well it was only a cheap meter. I wouldn't mind, but I did exactly the same the following day... with an old avo meter.
My rule since is to check twice measure once as opposed to in woodworking where you measure twice and cut once.
Stuart.
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Old 23rd Feb 2021, 12:01 am   #12
majoconz
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Default Re: DMM

One of my instructors many years ago said "It's better to know what your test equipment can not do, rather than not know what it can do".....

..and if all else fails "Read The Flaming Manual" or words to that effect. Mind you, some of those things that come from some far Eastern country do take a bit of translation.
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Old 23rd Feb 2021, 8:45 am   #13
The Philpott
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Default Re: DMM

Distraction is half the problem, and with me it's an age thing. Especially with multiple measurements some people don't grasp that they either need to stop talking or be somewhere else.

I have been gifted basic Motorola SW walkie talkies so that i can be hailed remotely- which is just fine!
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