2-wire digital voltage display accuracy
I had a few needs to for a simple voltage display that can handle the range of +5v to +12v. There’s a few different applications like displaying the state of a battery, a state of a power supply and so on. I was fairly interested to know how accurate these displays are considering they are only a few dollars each. I ordered these from Amazon.
I attached my Rigol DP832 display up it, set a particular value, then at the same attachment to the display attached my B&K DMM 2709B. The chart below shows the accuracy, which I find really amazing considering the low price.
| Value Set | Rigol DP832 Power Supply | B&K 2790B | Display | Diff from B&K | Diff from Value Set | Diff from value in percentage |
|---|---|---|---|---|---|---|
| 4.40 | 4.397 | 4.393 | 4.36 | -0.033 | -0.04 | -0.91% |
| 4.50 | 4.497 | 4.493 | 4.48 | -0.013 | -0.02 | -0.44% |
| 4.60 | 4.597 | 4.593 | 4.60 | 0.007 | 0.00 | 0.00% |
| 4.70 | 4.698 | 4.693 | 4.68 | -0.013 | -0.02 | -0.43% |
| 5.00 | 4.997 | 4.992 | 5.00 | 0.008 | 0.00 | 0.00% |
| 5.50 | 5.496 | 5.489 | 5.48 | -0.009 | -0.02 | -0.36% |
| 6.00 | 5.995 | 5.986 | 5.96 | -0.026 | -0.04 | -0.67% |
| 7.00 | 6.998 | 6.98 | 6.96 | -0.02 | -0.04 | -0.57% |
| 8.00 | 7.999 | 7.98 | 7.98 | 0 | -0.02 | -0.25% |
| 9.00 | 8.998 | 8.98 | 9.00 | 0.02 | 0.00 | 0.00% |
| 10.00 | 9.999 | 9.98 | 10.00 | 0.02 | 0.00 | 0.00% |
| 11.00 | 11.000 | 10.98 | 11.00 | 0.02 | 0.00 | 0.00% |
| 11.50 | 11.499 | 11.48 | 11.50 | 0.02 | 0.00 | 0.00% |
| 11.80 | 11.798 | 11.78 | 11.80 | 0.02 | 0.00 | 0.00% |
| 12.00 | 11.999 | 11.98 | 12.00 | 0.02 | 0.00 | 0.00% |
| 12.50 | 12.498 | 12.48 | 12.50 | 0.02 | 0.00 | 0.00% |
| 13.00 | 12.998 | 12.98 | 13.00 | 0.02 | 0.00 | 0.00% |