Where to procure meters

Discussion in 'General Electronics Chat' started by magnet18, May 11, 2011.

  1. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Hey all, I need to get 3 AC voltmeters, 0-15 volts, 3 AC voltmeters, 1-110V, 3 AC ammeters, 0-5A, 3 DC voltmeters, 0-15 volts, and 3 DC ammeters, 0-5A.

    And I would like to get these without going broke.
    And I want them to match visually, not ALL of them, I just want the AC voltmeters to match, and the DC voltmeters to match, and etcetera.

    Does anybody have any clue as to how to get these cheap? The cheapest I can find online is $15 a piece, so new is obviously not the way to go, since I need 15.
    Thoughts?
     
  2. PackratKing

    Well-Known Member

    Jul 13, 2008
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    Analog or digital ??

    I have used salvage meters from stereo multiplex in past. A genuine PIA to set up for the odd application, tho' you learn a ton of good stuff about full scale sensitivity & shunting in the process.......:D

    good idea to avoid the "VU" meters, as they were too busy during their original application, and unlikely to last very long
     
    Last edited: May 11, 2011
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  3. Jaguarjoe

    Active Member

    Apr 7, 2010
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    The odds of finding used matching meters for less than $15 ea is about zero. I've seen new analog meters here and there on the web for $10-$13. Ebay was one of those places, along with All Electronics, BGmicro, and Electronix Express. Futurlec might have a good selection too.

    New US made analog meters are $$.

    I've seen nice little LCD DPM's for $8 in many ranges but I'm not sure if AC amps was available. You could use an AC voltmeter and a shunt though. Same w/DC if you had to.
     
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  4. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Whichever costs less ;)

    I think $5 a pop is the max I'm willing to spend. If necessary they don't need to match...
    Not sure if a voltmeter with a shunt would work considering that I need this to be in with the device, and I need to draw as little power as possible. :/
     
  5. K7GUH

    Member

    Jan 28, 2011
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    I have seen new meters on the 'net for as little as $10.00 apiece, occasionally for $8 or $9. $5 prices seem to be available only at swap meets held under a blue tarp.
     
  6. shortbus

    AAC Fanatic!

    Sep 30, 2009
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  7. Jaguarjoe

    Active Member

    Apr 7, 2010
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    For $5, you might have to roll your own. Unlit LCD's should be pretty cheap. An 8 leg PIC with an ADC is pretty cheap too.
    There are voltmeter or DMM chips out there too.

    You could use LM3914 bargraph driver chips and LED's.

    A shunt to measure current shouldn't consume too much. Its value and size depend upon your parameters and the meter used, typically 50mv.
     
    Last edited: May 12, 2011
  8. radiohead

    Active Member

    May 28, 2009
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  9. Jotto

    Member

    Apr 1, 2011
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    why not use a programmable pic? you could have it monitor the voltages, an switch between them and just use one LCD. It would do voltage and current.
     
  10. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Yea, I think I'll look into the voltmeter chips since I have some single sided pcb's begging for an etching, if that looks too complicated I'll wind my own galvos, how hard can it be?

    I want a meter for each mainly because I want to see immediately if something is changing, so consolidating it all into one display wont work.
     
  11. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Have you ever looked inside an analog meter? :eek:

    Ken
     
  12. Jotto

    Member

    Apr 1, 2011
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    I am sure I have some lcd panels I could sent you if you like. We use them a lot in gaming. I save all kinds of stuff.

    Just looked at mine, they are almost 7"X1" and have the ability to backlight on the same unit. I don't remember who makes them, but I have quite a few.
     
    Last edited: May 12, 2011
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  13. Markd77

    Senior Member

    Sep 7, 2009
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    Have you seen this one?
    If you have a PIC programmer they should work out to about $3-4 each plus your time.
    You will need a few op amps too to amplify the voltage from the current shunts and to convert the AC to DC .
    The maximum value it normally displays is 65.53 but I can change that easily enough.
    http://forum.allaboutcircuits.com/showpost.php?p=342284&postcount=797
     
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  14. Jotto

    Member

    Apr 1, 2011
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    I am getting to crush a bunch of machines, and they have a lot of LED displays. If you want them let me know, think next week or so we are going to destroy them. I am not keeping that stuff.
     
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  15. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Yea, just did, and it looks do-able:cool:

    I remember that now, but I don't have a pic programmer...

    Thanks, but I have access to a ton of 7 seg's themselves, it's getting them to be meters that I need to work on. :/
     
  16. Jaguarjoe

    Active Member

    Apr 7, 2010
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    A Picaxe is a few pennies more but it does not require a programmer, just 2 resistors, a 3 wire cable w/DB9 and an old computer with a serial port. You can use a newer computer with a serial/USB adapter.
    They program in simple Basic, the program editor, a simulator, and 3 manuals are all free.
    The guys on the Picaxe forum are more than willing to help with anything you got.
     
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  17. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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  18. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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  19. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    You want something accurate enough to be of use.

    You want it cheaper than anyone can offer it to you(outside of someone selling stolen goods from his car trunk)

    Do you really think you will find 'good, useable' meters for less than $3 each?

    I want a reliable car for $100, but I doubt that my sincerest desire, no matter HOW MUCH I want it will deliver me a useable car for such a ridiculously low price.

    Perhaps now is a time to re-evaluate your needs and separate them from your wants. Reality bites and nobody wants to wait, but getting some super cheap junk meters will only serve to teach you the valuable lesson of waiting AND it will cost you some money too.

    My next thought is those cheap multimeters that Harbor freight and other places sometimes sell for 2 or 3 bucks at special sales times. I have used several and found them to be more than acceptably accurate. Some of them match my Fluke on low DC scales. Could you make up a panel and cannibalize the meters? Run them all off of one 9volt adapter. Again it would require you to wait till they run a special...

    Wait, or wait, or waste some money. Hmmm, decisions decisions. :)

    I'm sure you will do what is right for you after some more thought
     
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  20. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    Just FYI: the LED and LCD panel meters usually require an isolated power supply; and you can't measure the voltage that the meter is being powered by.

    [eta]
    Also, you would need separate isolated or "floating" supplies for each LED or LCD meter; you couldn't power them all using one isolated supply.
     
    Last edited: May 12, 2011
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