150F 2.7V super capacitorsTolerance -20%~+80%Voltage 2.7VSurge voltage 2.85VNominal impedance: AC 10 megaOhms, DC 14 megaOhmsWorking and storage temperature range -40~+60?Lifecycles: Standard charge-discharge mode > 100000 cycles,?C/C, ?30%, ESR ? 4 times specified ESRDimensions: ?D: 25.0±1.0mm, L: 50.0±2 .0mm, H: 6.8±0. 5 mm, P: 10.0±0.2mm
But how long is 2 150F cap's in Series giving a little over 5v going to power a standard Arduino Uno?
Quote from: cjdelphi on Oct 23, 2012, 04:07 pmBut how long is 2 150F cap's in Series giving a little over 5v going to power a standard Arduino Uno?Maybe Grumpy can calculate that for us...I'm wondering where you're going to find enough electrons to charge it up.
No, that would be in parrallel.If you wire two capacitors in series, the voltage is shared between then proportionally to their capacitance (Q = VC where Q is the charge on the capacitor, which would be the same amount on each). If they both have the same capacitance, then the voltage (in this case 5v) would be shared between them equally, so each would see only 2.5V. The maximum allowed would be 5.4V, not taking into account any small difference is capacitance. 5V is less than this, however 5V nominal could have voltage spikes or noise which may expose the capacitors to more than they are rated for.
Forgive my total lack of basic electrical knowledge, but doesn't wiring these in series actually make the voltage through the whole circuit including the capacitors themselves 5.4V and exceed the specification of the two capacitors?
dv i---- = --- dt C
i * t ( Vi - Vf ) = -------- C
( Vi - Vf ) * C------------------ = t i