Apr 252015
 

Ive been looking for a cheap small voltage display for a project I’m working on and I turned to eBay to try a few of the cheap ones out.
I dont need anything spot of accurate but an indication of what I’m supplying.

My search led me to this one

It looks small and it was certainly cheap enough at 99p delivered.
It arrived today and it doesn’t look too bad.

I hooked it up to my power supply to check its accuracy and usefulness.
The description claims this thing can display from 2.5v – 30v so lets test those claims out.
NOTE: I really struggled getting a clear shot of the display with the useless HTC One camera and the fluorescent lights but you can make it out.

With the PSU set at 2.5v we get this:

Not bad at all. What happens when we go lower? Well I got to 2.489v and the display starts flickering like mad.

At the lower voltage of 2.5v the display is a bit dim. Perfectly readable but dim.

Next, 3.3v

And 5v

I did a bit of extra testing around the 5v area mainly as this is the voltage I’m going to be operating it at.
I tested at 5.2v

And to check the accuracy I checked it at 5.125v and 5.126v.

I’m happy with that even if I don’t need the accuracy too much.
Next up I tested 12v

20v

Finally I just tested its claimed maximum of 30v

The display gets a lot brighter at this voltage.
This unit I got didn’t need any adjustment but there is a small pot on the back to adjust it if required.

Its certainly not the best in terms of build quality but for my specific needs I’m quite happy with this really.

 Posted by at 11:52 am

  5 Responses to “Cheap voltage display”

  1. Pretty good. eBay link?

  2. Cheers!

  3. Got a few of them somewhere as they are good to add to edge connectors to show the voltage the pcb is getting…. Have I put them on my cab…. no I have forgotten where I put them :/ but great little things for a jamma edge connector

    – Ben

  4. oh and forgot to add…. I may get some of these if I don’t find the ones I have as they have pretty colours and apparently a better range (as we guess probably doubtful lol)

    http://www.ebay.co.uk/itm/251673640887

    – Ben