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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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Thread Tools |
13th Feb 2021, 11:40 pm | #1 |
Tetrode
Join Date: Nov 2020
Location: Udine, Italy.
Posts: 59
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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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14th Feb 2021, 12:09 am | #2 |
Tetrode
Join Date: Nov 2020
Location: Udine, Italy.
Posts: 59
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Re: DMM
it’s photo of my tester
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14th Feb 2021, 1:03 am | #3 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,528
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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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14th Feb 2021, 8:16 pm | #4 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,173
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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 |
14th Feb 2021, 10:38 pm | #5 |
Tetrode
Join Date: Nov 2020
Location: Udine, Italy.
Posts: 59
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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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14th Feb 2021, 11:19 pm | #6 | |
Heptode
Join Date: Mar 2017
Location: Cedar Grove, Wisconsin, USA.
Posts: 823
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Re: DMM
Quote:
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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15th Feb 2021, 1:53 am | #7 | |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,085
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Re: DMM
Quote:
See again post #4
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17th Feb 2021, 9:46 pm | #8 |
Heptode
Join Date: Jul 2009
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 722
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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 |
18th Feb 2021, 8:37 am | #9 | |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 7,639
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Re: DMM
Quote:
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18th Feb 2021, 10:19 am | #10 |
Pentode
Join Date: Oct 2006
Location: Brackley Northamptonshire, UK.
Posts: 240
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Re: DMM
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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18th Feb 2021, 12:04 pm | #11 | |
Hexode
Join Date: Dec 2012
Location: Carmarthen, Carmarthenshire, UK.
Posts: 268
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Re: DMM
Quote:
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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23rd Feb 2021, 1:01 am | #12 |
Heptode
Join Date: Jan 2008
Location: Ashhurst, Manawatu, New Zealand
Posts: 570
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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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23rd Feb 2021, 9:45 am | #13 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
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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! |