# If stored capacitor is used as source, what is the maximum current we can expect from this source?

Discussion in 'General Electronics Chat' started by ICD_life, Nov 12, 2014.

1. ### ICD_life Thread Starter New Member

Nov 12, 2014
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For example if I use a storage capacitor in harvesting Solar PV cell. To further use this storage capacitor as source to any application. How much load current can it provide?

P.S. Kindly correct me if my terminologies are wrong and help me understand. Looking forward for an answer.

2. ### ronv AAC Fanatic!

Nov 12, 2008
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1,449
It depends..... It can supply a lot of current for a short period of time or a little current for a longer time.
The formula is time = resistance X capacitance in farads. Where the resistance is you load.

3. ### Lestraveled Well-Known Member

May 19, 2014
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1,217
Perhaps a more accurate formula is, delta V/delta T = Amps/capacitance. Or more simply said, You can draw one amp from a one farad capacitor and the voltage will drop at the rate of one volt for every one second. (the rule of ones.)

4. ### ICD_life Thread Starter New Member

Nov 12, 2014
9
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Thank you all. Sorry.

I am not sure how to explain my doubt kindly find the figure attached [ I(avaerage) = (Vin-Vout)*C/T;]. The storage capacitor say(500pF) is charged to 1.5V and then used in charge pumps to double the voltage.

Is my understanding right "Current out of the storage capacitor is based on load i.e. the charge pump in here"?

Nov 12, 2014
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6. ### wayneh Expert

Sep 9, 2010
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Ohms law. The instantaneous current will depend on the instantaneous voltage difference divided by the combined series resistance of the wires and components. Assuming the wires are short and the capacitors fresh, I'd guess the resistance is in the 1Ω range, ±5X.

If you need an average or cumulative value, you'll have to integrate the equation over time.

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