Believe It or Not!

guido

Well-known Member
Hello,

I needed it to charge a single set of batteries on a pack I was working on, so I hooked up the amp meter, polarity don't matter on a digital meter, and measured .96 amps. They are Lithium cells. Then I remembered some one on this board said that an amp probe would measure the amps as well. It worked.! It may not show well in the picture, but that probe was measuring a indicator handle thickness under one AMP. BELIEVE IT OR NOT! Here is the picture..........

Guido.
a186937.jpg
 

Years ago when home furnaces t-stats had an adjustable resistors in them to set the heat differential, I made a 10 loop coil and used my Amp Probe to measure in 1/10's to set that resistor. A 3 amp reading = .3 amps.

Dusty
 

measuring dc current?? I thought it was only ac current that could be measured by an amp probe. Especially one that old.
 
Dr.
An amprobe will not measure DC from a battery. It will measure the current from a charger, which is pulsating DC. The probe can't tell the difference between AC and rectified AC.

Just try it on a battery charger, it does work. I do it all the time.
 
Sorry, wrong.

DC amp clamps are plentiful.

They just aren't the 15-25$ ones.

Milwalkee makes a 600a version.

Craftsman made one. Plenty of people make them.

DC inductive amp measuring is nothing new..
 
Milwaukee

My phone auto corrected that wrong.

Model 2237-20

Its like a 230$ meter....

Like I said.. the 25$ jobs are all ac amps.

Buy a REAL meter, and you can get DC amps.
 
Hello Geo-FH,In

I was using the charger to bring 1 set of lithium cells up to voltage with the other 4 sets. I got the charger for the pack to use, but it won't charge. Those are replacement cells, but low on voltage compared to the other sets. They all measure 4.2 volts. The charger is what I put together years back. AC output is rectified through a diode bride, then a rheostat through a mosfet and out. 8 volts or so and at least 5 amps. The probe was around one of the charger leads, while the amp meter was in line on the other side. Considering the circuit, I'm thinking that it is not a pulsating, but a linear output? All I know is that the amp probe is reading the same as the digital meter, spot on!

Guido
 
Hello sotxbill,

I thought so as well. The amp probe and the digital meter are show the same current!
Believe it or not,

Guido.
 
Hello Dusty MI,

YA, did that wrap thing also. Now days you can buy one ready made. Plug in the wall with different amount of loops per coil,

Guido.
 
Soundguy,
From the pic, it looks like Guido has an old school analog amprobe that wouldn't measure DC amps. I had one like his about 50 years ago.

It will however measure rectified AC, because rectified AC has changing magnetic field.

I never invested in a clamp on DC ammeter, instead I have an old auto style meter.
 

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