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Unread 05-03-2007, 19:06
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Re: Non Frc: Electrical question series and parallel

Quote:
Originally Posted by Tri_Lam View Post
thanks but im not sure if i was clear enough though. we're arranging solar cells not battery cells to help power a solar car. ill reword my earlier question

arrange 7 solar cells w/ .5 voltage with 6 amp hrs into two series one with 4 solar cells the other with 3 you get 4 solar cells withg a voltage of 2 volts and 6 amps while the other is 3 solar cells producing 1.5 volts with 6 amps. then putting both series into a parallel connection in theory gives us 12 amps but what is the voltage output? is it average? does the electricty runover to the other cells?

if my question is confulsing tell me n ill try my bset to simplify it
As others have said, the cells have an internal resistance, and this will become the limiting factor.



The difference in voltage between the two photo-voltaic arrays will result in current flow limited by the internal resistance of the PV cells and the interconnecting wiring.

Given that the voltage output from the PV cells changes based on the amount of energy they receive, even wiring identical PV cells in parallel isn't a good idea for that reason alone.

With the low voltages you are proposing, even a Schottkey diode (which has a lower forward drop than a traditional silicon diode) represents a large voltage drop relative to your output voltage.

It would be better to connect your PV cells in series, and then using a high efficiency regulator, such as a switching supply, to drop the resulting output down to whatever voltage the load would need.
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