Velleman PMLCD DCV Meter Configuration

Discussion in 'General Electronics Chat' started by maw455, Jul 28, 2016.

  1. maw455

    Thread Starter Member

    Jul 20, 2016
    30
    1
    I picked up a Velleman LCD DCV panel meter today, and the instructions that came with it are abysmal on how to configure it for voltage readings above the 200mV default setting. For example, to configure it for 0-20V, the instructions say:

    Disconnect jumper wire in RB
    RB = 9.9M Ohm RA = 100K Ohm

    To change the decimal point for 20V range:

    Short circuit P2-P0

    That's it - no circuit diagram or pictures to assist. I found RA and RB on the board, but it looks like they have SMT resistors already in place and there is no jumper wire on RB. Also, P1 - P3 are labeled on the board, but not P0. However, after metering the SMT's it turns out RA is 10M and RB is in fact a jumper.

    After a bit of digging, I came across this in the Velleman forum which helped a lot and thought I would share it for anyone looking for the same answers in the future:

    http://forum.velleman.eu/viewtopic.php?f=18&t=7997

    Note that the forum post says NOT to remove the resistor in RA, which was suggested in a much older thread here on the LED version of this meter.

    Clicking on the first link provided in the post takes you to this Velleman support page

    http://www.velleman.eu/support/faq/?code=PMLCD&country=be&lang=en

    which has a handy photo of the board with the relevant pin locations identified.

    The meter did come packaged with a set of resistors valued at 1K, 10K, 100K and 10M for the various RA and RB configurations.

    Hope this helps.
     
  2. #12

    Expert

    Nov 30, 2010
    16,261
    6,768
    Note to helpers on this site:

    There are no questions to help with in post #1
     
  3. maw455

    Thread Starter Member

    Jul 20, 2016
    30
    1
    OK - should I have posted this in reply to the question posted in a thread that is more than 5 years old? Is there a more appropriate section to post helpful information for problems others have encountered? I'm not trying to be facetious, just don't want to repeat my mistake in the future.
     
  4. #12

    Expert

    Nov 30, 2010
    16,261
    6,768
    I didn't say you made a mistake, but people generally expect Threads to start with a question of some sort. I was trying to save the regular denizens from reading your whole post trying to find the question because the most likely reader already knows how to do this and expects to point you to the right information.

    In my opinion, answering a 5 year old question is not likely to help the person who wanted an answer. It is likely that he didn't set the project aside and wait for your help for 5 years. (You can click on their name to see if they have checked in recently.)
    If you feel a need to post answers to long dead Threads, one helpful thing might be a title that says something like, "tutorial", or you might take pictures of the board and post in the Completed Projects Forum. Another option is your personal blog space on this site. If you post there, you can just give future people a link to your blog and thus, answer them quickly with a well thought out answer you wrote a long time ago. That one is my favorite answer. I have done some blogs about very detailed or very nit-picky subjects and use them for a quick reference for the noobies.
     
  5. maw455

    Thread Starter Member

    Jul 20, 2016
    30
    1
    Understood, and thank you for taking the time to clear this up.

    I found my blog space and posted it there. Good suggestion.

    To the moderators, you can close this post if you want to avoid confusion.
     
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