Jump to content

Digital MultiMeter reviews


Recommended Posts

The guy behind this is not just very competent, but also generous and systematic in sharing his analysis. I have learned a lot about practical electronics and was able to chose a modest DMM that altough satisfying for general use, is not good enough for complete quartz module testing. The search continues.

https://lygte-info.dk/info/DMMinfo.html

 

Link to comment
Share on other sites

Some of the low cost meters do have frequency ranges, and since a quartz watch typically operates at a relatively low frequency, they should be able to measure the crystal fairly accurately. Some may even do a reasonable job of measuring 1Hz.  I'll have a play with mine and see what I come up with.

Even the really cheap ones, particularly if they are based on the DTM0660 chip-set are often capable of true RMS and frequency measurement.

I have a really cheap Victor VC 921,  that I (as my alter ego "itsthatidiotagain") hacked about a while back.
https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921/

http://www.kerrywong.com/2016/03/19/hacking-dtm0660l-based-multimeters/#comment-874169
There are also some of the Aneng models that might fit the bill.

I wouldn't trust any of the cheap'n cheerful Chinese low cost meters near "real" electricity, as their CAT ratings are usually unverified, and wildly exaggerated, but for this kind of work, they are probably fine.

Edited by AndyHull
Link to comment
Share on other sites

1 hour ago, jdm said:

The guy behind this is not just very competent, but also generous and systematic in sharing his analysis. I have learned a lot about practical electronics and was able to chose a modest DMM that altough satisfying for general use, is not good enough for complete quartz module testing. The search continues.

https://lygte-info.dk/info/DMMinfo.html

 

   right you are,  the simple "multimeter"  is not sensitive,  presisign, enough  for electronics.     I can't remember the one that was.  i'll drag the one out that is.   also,  accutron  had a special meter for that mvt.  (I have one  of  those too).   ALSO;  I think we have a eleictronics engineer in this forum?   OH - how I hate eleictronics  !    vin

Link to comment
Share on other sites

Hi   I found the best meters for quartz watch work were the moving coil meters especially when checking the coil and pulses from the Block. I used to use a    TAYLOR 8 or an AVO meter, both large meters but very sensative,  You can see the pulses on the needle..   I now use a purpose build Quartz analyser which uses a LED array to determine the movement functionality and battery state.

Link to comment
Share on other sites

3 hours ago, AndyHull said:

Some of the low cost meters do have frequency ranges, and since a quartz watch typically operates at a relatively low frequency, they should be able to measure the crystal fairly accurately.

Correct. But I was referring more to measuring the very low absorbed current, and resistance/continuity of the coil without blowing it told in a recent topic. The latter specification of low voltage ohmeter required your dear to scour through the entire database to find that only 7 models use 0.4V or less, fortunately all but one are very cheap. I'll get one and will update this thread once I can verify that it does the job correctly. 

3 hours ago, AndyHull said:

I wouldn't trust any of the cheap'n cheerful Chinese low cost meters near "real" electricity, as their CAT ratings are usually unverified, and wildly exaggerated, but for this kind of work, they are probably fine.

An aspect well highlited in all the reviews of the website above.

1 hour ago, watchweasol said:

Hi   I found the best meters for quartz watch work were the moving coil meters especially when checking the coil and pulses from the Block.

Probably "taut band" meters. I've learned myself what that is on this occasion. I like the Sanwa and I'm thinking to get one, again not all can measure very low current. The Chinese also make some decent products.Back in the days even my coutrye made a very accurate and versatile one. The manual even had diagnosis and repair instruaction, you can still buy used but isn't cheap.

Link to comment
Share on other sites

Hello    A few years ago I had this setup for quartz watches build on the lines of the seiko test set It enables you to drive the watch from an external source, test the upper and lower voltage limits and also current consumption. the black box was connected to the meter and the readings taken. One could  also test batteries and drive watches using the 3v coin cells.  The circuit was designed by officers of the AWCI i think as it is quite a while ago.

DSCF3283.JPG

DSCF3284.JPG

DSCF3285.JPG

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Two pins or screwdrivers angled out slightly, pressing through from the barrel centre from the opposite side so they contact just clear of the hole in the lid? eg. Strap pin driver needles or similar.
    • That's a good idea - shrinking down the nut and wrench size from the old casebook trick!
    • I missed this earlier. The dial isn't going into the holder, it should sit proud of it. This is what I am currently using which I print for each different movement.    
    • I didn't think pulling to set position would work harden the spring, in that position it is stressed where the arm starts. By work hardening i meant rapid polishing at that point, a bit like polishing a pivot work hardens as it compresses the steel. I doubt polishing by hand would achieve much in that respect though. Its finished, arm polished up mostly at the join to the bridge's main body. I'm ok with it, the screw holes aren't great as i had to open them up by redrilling and positioning it was difficult, I'm not much use with a loupe, opening up with a file might be a better option for me or i could just use the correct drill size 😅. And the detent is way too deep, i had to guess that with the stem release out of position and sat on top, but i only took one measure and went for it, no slowly slowly catch your monkey 😅. First go I'm happy , well sort of, it works and thats a big thing for me, next one will have a bit more finesse.  Anyone thats interested, after filing, i used a 2000 grade home made diamond  micro file and then 20 micron film, the film is much better than wet and dry, more stable to use and doesn't shed cheap grade grit everywhere , then auto polish on a sponge pad.
    • I'm assuming that every time you set the watch you are work hardening the detent spring, maximum hardening is  where it meets the plate due to maximum deflection.   That's why it snaps there.  The Young's modulus may be the same but after it's reached its maximum yeid strength it breaks.  My mechanic engineering is very rusty, correct me if I'm wrong. 
×
×
  • Create New...