DMM amp reading issues.

Flashlight Modding and DIY Parts
1

I felt you guys here would know DMM's better than asking in "General Info".

I have read the rather simple guides to taking tail cap amp settings, And to make it easier to start im using a single mode light.

Ive been trying to take some tail cap amp readings and ive been getting some odd results. First is using my dads nice Fluke meter its giving no readings off the fused 10amp lead settings. It also doesnt trigger the light to an "ON" state. That i need to check for a blown fuse, But he said it was fine last he checked, So if it isnt the fuse ill report back.

Secondly is my meter, On the 10amp fused settings it does fire the emitter, But im getting a reading of 10.76 with no mention of amps or ma's and this was on a 14500 Li-ion cell. If i put in a 1.5v NiMH cell i get reading on an old cell of 18.78 or so and it would max out the scale with a fully charged AA NiMH.

Im thinking my meter with the odd readings may be a lost cause, And im gonna dig into my dads Fluke and check the fuse and hope it has a physical fuse and not a relay.

Lastly, If all else fails can you recommend a good DMM that will be decently accurate and low priced. Im kinda afraid to buy from China on this, But most likely anything i buy here in the USA was made in China anyhow.

2

Sounds like both meters are broken.

For the Fluke, a bad fuse is the most likely option, but it could also be bad probes or a bad jack, or the meter is bad.

For yours, are you using the right jack (if it has separate 10A and mA jacks), and on the right setting?

--Bushytails

3

The probes were fine testing voltage with the fluke, I still need to check the fuse but my cat decided it was nap time and is using me as a bed.

I used the 10A fused setting and put the +positive into that jack and set it to 10A on the dial for my meter.

After i check the Fluke i may go DMM shopping.

20 years ago i almost finished EE degree and dropped out like an idiot, So i have some experience but i have forgotten alot also.

Suggestions on a low priced quality replacement?

4

Could be an stupid question, but ¿Did you must press (in my Fluke 179, the yellow) button to switch from AC Amps to DC amps?.

5

If that were the case, the flashlight would still light.

--Bushytails

6

To check the 10A range fuse integrity, just switch to "continuity" (or "ohms") and put the leads in the outer two jacks. (RED + Voltage jack and the RED + 10A range jack) Touch the leads together. It will beep if the fuse is good.

If no beep (or not near-zero ohms), check the leads by putting them back where they belong and touch them together.

This always works for 10A range fuses. YMMV when testing fuses in separate lower range current jacks.

7

Crux called it right on the Fluke, No continuity beep in that setting.

Mine did beep tho, But may be just a cheap meter. But once i look into the Flukes fuse ill test it against it and see if its ready to be trashed.

Thanks.

8

You can get the cheapo red meter at harbor freight for the kind of stuff we're doing. They work remarkably well for the price.

9

Thats a good idea, I need to visit HF and Home Depot as im building a battery holder for my hobby charger so i dont have to keep charging one cell at a time. But i do have free access to the Fluke meter so interest of saving money i may just keep using that.

I did get some what i think are odd readings at the tail of a Sipik zoom clone, With a 14500 i got 1.4amps and with a AA NiMH Imedion cell i got a little over 2 amps. This doesn't seem right, But with the lower voltages it may be pulling more amps to compensate?

Now that i have the Fluke working ill move on and test a few other lights that are Li-Ion only and see how it responds to settings changes.

Does those reading sound possible or right? Or am i still in need of a new meter?

10

If you want to save all of $4, you can wait until HF has them for free w/ coupon.

The sk68 reading is correct. It's DD off of 14500 and boost circuit for AA's (to reach the Vf of the led).

11

Im starting to take nothing for granted with flashlights despite all my older teachings in EE 20 years ago. I knew about boost circuits but i didnt expect them to boost amperage so much higher than even the output of a Li-Ion cell.

Ill just stick with this Fluke for now, Its a good one with sentimental value as my dad used it in his tool box before he retired.

12

Did you just say you were thinking about trashing a fluke?? and are discussing buying B.S. from harbor frieght...I think I missed something here .. i have a2 flukes and a friend of mine gave me a harbor fieght meter .. it's pure crap

yeah .... get rid of that fluke..and buy a garbage multi meter .that makes perfect sense

13

-2 points for both of you for not reading the whole thread.

14

I've been quite happy with fluke... best tech support ever, possibly. I was repairing a very, very old benchtop digital multimeter of theirs (nixies!), and decided a schematic was required. Their website had PDFs of a lot of service manuals, but nothing nearly as old. I emailed them asking if they had any service information for it, they replied that no, they didn't have any, and anyone who had even seen one was dead or otherwise not with the company, but they'd see what they could do. About two weeks later I got an email saying they bought an old copy of the manual, scanned it, and here's the PDF. So keep yours, no matter how old it is - they'll always help you fix it. :)

--Bushytails