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$1.55 Digital Voltmeter — Parallax Forums

$1.55 Digital Voltmeter

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Comments

  • RDL2004RDL2004 Posts: 2,554
    edited 2013-10-04 13:27
    Don't really need any volt meters, but these have "digital tube" displays, so I bought 3 for five bucks :)
  • jmgjmg Posts: 15,173
    edited 2013-10-04 14:22
    hehe "digital tube"
    I like the 4 digit blue one, for $3.75 and free shipping.

    Especially if it had mini-auto range, so can do 2 DP placements like 12.34V and 9.874V - but that is not mentioned.
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2013-10-19 06:50
    Anyone received their order yet?

    I think the order said expect delivery on Oct 18 to Nov 4.
  • RDL2004RDL2004 Posts: 2,554
    edited 2013-10-19 08:04
    Mine haven't shown up yet. They were ordered on 10/4/13 and estimated delivery is Oct 17 to Nov 4
  • ercoerco Posts: 20,256
    edited 2013-10-19 09:02
    Nuttin' honey.
  • User NameUser Name Posts: 1,451
    edited 2013-10-19 09:28
    I've got a serious question about this. Several of the Chinese buck converter boards I use are equipped with a self-powered three-digit voltmeter. They work fine at higher voltages but are very coarse or granular at lower voltages. I wonder if the voltmeter of this thread has overcome that problem. I'd love to order several of these, but I may stay tuned to see what others report, first.
  • CuriousOneCuriousOne Posts: 931
    edited 2013-10-20 02:36
    I have bought similar looking ones from taobao for $0.6/ea (pack of 10). Precision is around 10%.
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2013-10-21 13:16
    Got mine today - ordered on Oct 4.

    Measured a 12V gell cell at 13.2v - matched my digital VOM
  • ercoerco Posts: 20,256
    edited 2013-10-21 13:45
    Then I sure as heck better get mine today! Also ordered Oct 4, and I'm in LA: closer to China and a gateway city. :(
  • mindrobotsmindrobots Posts: 6,506
    edited 2013-10-21 14:03
    erco wrote: »
    Then I sure as heck better get mine today! Also ordered Oct 4, and I'm in LA: closer to China and a gateway city. :(

    But Jiujiang, PR China has been a sister city of Louisville since 2004! :smile:

    (ok, LA has Guangzhou, China but that doesn't support my point!)
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2013-10-21 14:29
    erco wrote: »
    Then I sure as heck better get mine today! Also ordered Oct 4, and I'm in LA: closer to China and a gateway city. :(

    Ah, but Louisville has Worldport - a worldwide air hub for UPS - not sure if UPS was involved though...
  • ercoerco Posts: 20,256
    edited 2013-10-21 20:08
    Nuttin' honey... :(

    Maybe my local PO screwed up... AGAIN.
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2013-10-22 06:08
    Since these volt meters are self-powered, I checked out how much current they draw.
    At 5 volts, the meter was drawing around 21mA.
  • xanaduxanadu Posts: 3,347
    edited 2013-10-22 06:53
    erco wrote: »
    Nuttin' honey... :(

    Maybe my local PO screwed up... AGAIN.

    I ordered Oct 4th and got mine yesterday. They were USPS signature required so I had one of those slips buried within a pile of junk mail.
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2013-10-22 06:58
    My package was delivered by USPS but did not require a signature.

    Did you order yours from "electronicsfrom2006"?
  • xanaduxanadu Posts: 3,347
    edited 2013-10-22 07:50
    Yes, and it came from a "Jing Sheng Zhou". I was wondering about the signature myself, figured someone from the institution may have found me.
  • ercoerco Posts: 20,256
    edited 2013-10-22 08:27
    Ron Czapala wrote: »
    Since these volt meters are self-powered, I checked out how much current they draw.
    At 5 volts, the meter was drawing around 21mA.

    OK, Now I'm sure mine are late because I'm getting the newer version which has higher efficiency and uses low-current LEDs. :)
  • mindrobotsmindrobots Posts: 6,506
    edited 2013-10-22 08:49
    erco wrote: »
    ...and uses low-current LEDs. :)

    Maybe they switched over to those "digital tubes" for you? :smile:
  • RDL2004RDL2004 Posts: 2,554
    edited 2013-10-22 08:49
    They were USPS signature required

    I sure hope mine aren't. It'll take more than $1.55 in gas to drive to the Post Office and get them.
    That would be pretty unusual, since "signature required" is supposed to cost extra.
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2013-10-22 09:00
    erco wrote: »
    OK, Now I'm sure mine are late because I'm getting the newer version which has higher efficiency and uses low-current LEDs. :)

    Yeah, but they display the voltage in octal...
  • ercoerco Posts: 20,256
    edited 2013-10-22 21:46
    Maybe one of them is displaying in octal...

    Nope, one works fine, the other displays 38% of the real voltage. Ah well, I'm sure the seller will replace/refund.
    CAM01030.jpg
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  • garfieldguo222garfieldguo222 Posts: 1
    edited 2013-10-23 02:09
    erco wrote: »
    Maybe one of them is displaying in octal...

    Nope, one works fine, the other displays 38% of the real voltage. Ah well, I'm sure the seller will replace/refund.

    Do not be so confident:innocent:
    I mean, once you buy something even after the change will drag you for a long time.
  • ercoerco Posts: 20,256
    edited 2013-10-23 07:06
    Actually Ebay sellers in China are very reliable and eager to please. This seller already refunded my money overnight, so I would buy from him again. One bad apple (or DVM) don't spoil the whole bunch. :)
  • xanaduxanadu Posts: 3,347
    edited 2013-10-23 09:16
    erco wrote: »
    Maybe one of them is displaying in octal...

    Nope, one works fine, the other displays 38% of the real voltage. Ah well, I'm sure the seller will replace/refund.

    There's a little trim pot on the back, I haven't messed with it but maybe it's a calibration.
  • User NameUser Name Posts: 1,451
    edited 2013-10-28 17:14
    Ultimately I ordered three similar modules - differing from the OP mostly in that they split out the V+ line from the Vmeasure line (which can always be joined together as long as you are measuring something 2.5V or above). This allows measurement all the way down to 0V).

    Anyway, I needn't have worried about granularity at low voltages...all three modules (red, yellow, and blue digits) work great across the entire range (0 - 32V). So why didn't they put modules like these on the buck converter boards I bought? :confused:

    Anyway, thanks to erco for bringing attention to the genre. These are very handy products at a great price.
  • RDL2004RDL2004 Posts: 2,554
    edited 2013-11-18 13:26
    I didn't receive mine until exactly one month after I purchased them. That's the longest I've ever had something take to arrive from Hong Kong or China, and I didn't get around to testing them until yesterday. They all work. According to my Fluke 87 III, all three of them read 0.02 - 0.03 volts on the low side. Not very much off at all and at least they're consistent. I can confirm power consumption of around 20-23 mA

    These are still available but the price is now $1.65 - not a bad deal at all.
  • xanatosxanatos Posts: 1,120
    edited 2013-11-18 14:03
    I ordered 5 of these, arrived last week. Very long wait... but they're here, all 5 work, and are all within a few hundredths of a volt of what my Fluke reads. For the price I'm very happy. I can put one of these in every personal project I do!
  • ercoerco Posts: 20,256
    edited 2013-11-18 16:29
    Glad to hear you like 'em. I guess the word is out, 'cuz the price (formerly $1.55) has skyrocketed to $1.63.

    Just my 8 cents.
  • Mark_TMark_T Posts: 1,981
    edited 2013-11-18 17:56
    Anyone tried modding them to measure a separate voltage than their supply? If its easy to do could be
    handy
  • ercoerco Posts: 20,256
    edited 2013-11-24 19:22
    Down to $1.34 now unless Amanda, Beau or Duane can beat cheap old man erco. :)http://www.ebay.com/itm/Mini-DC-2-5-30V-Red-LED-Panel-Voltage-Meter-3-Digital-Display-Voltmeter-E0Xc-/161156251104?pt=LH_DefaultDomain_0&hash=item2585a93de0
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