I did two (2) experiments with a 20V DC power supply and 4 capacitors in series. All series connections were checked to insure proper polarity.
Experiment with four (4) 22uF 16V tantalum capacitors:
20V-------(+) C1 (-) ----- (+) C2 (-) ----- (+) C3 (-) ----- (+) C4 (-) ----- GND
The voltage...