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Measurements

A project log for Fully analog digitally controlled voltage source

Voltage is set with three BCD switches with a step of 10mV

klimaKlima 05/30/2023 at 21:290 Comments

Theoretical results for error calculation, now with measurements!

I made 2 prototypes and measured the output voltage of both prototypes. The results are shown below.

Ambient temperature during measurements: 24°C

Supply voltage: 9.99V

Voltmeter used: Brymen BM857a

Prototype #1
set value [V] measured value [V] error [mV] error [%]
0 0.03528 35.28 ---
0.15 0.15125 1.25 0.833
1.34 1.34085 0.85 0.063
1.79 1.79069 0.69 0.039
2.12 2.12023 0.23 0.011
3.12 3.11964 -0.36 -0.012
3.77 3.76934 -0.66 -0.018
4.33 4.32833 -1.67 -0.039
4.85 4.8478 -2.20 -0.045
5.25 5.2482 -1.80 -0.034
6.49 6.4867 -3.30 -0.051
6.95 6.9462 -3.80 -0.055
7.28 7.276 -4.00 -0.055
8.28 8.2811 1.10 0.013
8.66 8.661 1.00 0.012
Prototype #2
set value [V] measured value [V] error [mV] error [%]
0 0.00339 3.39 ---
0.15 0.14943 -0.57 -0.380
1.34 1.33838 -1.62 -0.121
1.79 1.78795 -2.05 -0.115
2.12 2.11742 -2.58 -0.122
3.12 3.1162 -3.80 -0.122
3.77 3.76559 -4.41 -0.117
4.33 4.3237 -6.30 -0.145
4.85 4.8431 -6.90 -0.142
5.25 5.2427 -7.30 -0.139
6.49 6.4809 -9.10 -0.140
6.95 6.9405 -9.50 -0.137
7.28 7.27 -10.00 -0.137
8.28 8.27 -10.00 -0.121
8.66 8.6495 -10.50 -0.121
Relative error with dots indicating measurement results: Yellow - prototype #1, red - prototype #2
Absolute error with dots indicating measurement results: Yellow - prototype #1, red - prototype #2

As can be seen, the measurements lie within the limits indicated by the simulation.

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