# voltage doubler for solar panel

#### majorkuso

Joined Aug 21, 2009
56
I have two solar cells wired in series. I would like for someone to help me design a circuit to doubler the voltage or if not exactly double increase it by a margin. the ratings are 19.4 volts at 150milliamps. the purpose is to be able to create a 5 to 24 volt charge station for batteries. I would like for the circuit to be capacitor driven. these readings are no load readings. what is the best way to find out the full load drop for regulation? connecting a 5k resistor in series and seeing what it is pulling out minus resistor v drop? not sure on calculating full load regulation. I could put diodes on the solar output to block reversal voltage from the battery then read the output voltage of the panels. from its leads.

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#### Bernard

Joined Aug 7, 2008
5,227
Is the 19.4 V an open circuit reading of two panels in series? Maximum power occurs when panel is loaded dovn to 70% of open circuit V according to my measurements.
1982 Radio Amature Hand Book has a cap. doubler for NiCd's, here's another similar: http://www.uoguelph.ca/~antoon/gadgets/carnc12.htm

#### majorkuso

Joined Aug 21, 2009
56
It is open with no load on the circuit.what exactly do you mean by open circuit. the only time i have heard of open circuit is in refrence to open and closed circuits. by the way the link shows no file found. Also if anyone is wondering why I chose cap driven it is because I have more capacitors than I know what to do with and range in value from 0.1uF to 120000uf. I forgot to mention that i would prefer a transformer less application, but making a transformer application wouldn't hurt to expand my knowledge.

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#### Bernard

Joined Aug 7, 2008
5,227
Open circuit measurement, just as you said , measurement with no load. Attached is doubler from Ugelph with diodes changed by Tony van Roon ? to shottky 1N5400, from 1N2002. Q is a linear audio power amp.10 W. For lead acid battery might look at PB137 by ST for regulator. The AARL handbook doubler is similar, but uses a 555 with complementary transistor driver.

#### Bernard

Joined Aug 7, 2008
5,227
Looks like I put post in wrong pot.

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#### majorkuso

Joined Aug 21, 2009
56
I will give the schematic a try with multisim and see what happens. I have a question concerning multisim since i have had no formal training in it. Can i assign a current level to my voltage source or must i use a currenty controlled source in conjunction to my voltage source? the sinmplest thing would be to add another cell in series, but that would not increase my circuit design and implementation knowledge now would it.? correcvt me if I am wrong,but I can pit a low ohmage potential divider (perhaps a potentiometer) at the output voltage to control the output voltage variation correct?

#### majorkuso

Joined Aug 21, 2009
56
ok when i run a simulation in multisim aka electronics workbench. I do not see a gain in volt. the only difference is that I have a tda2030 instead of the two in the schematic you posted the tda2030 is a 10watt amp. I have tried everything i can think of in the sim. I have previously created ac to dc stepup conversions with one being a full wave bridge and the other being a half before and got a little over half voltage output.

#### Bernard

Joined Aug 7, 2008
5,227
TDA2030 is a 14W, dual supply amp; TDA2003 is a 10W, single-ended supply amp. Did you supply + feedback & it would not oscillate? To charge batteries it would be helpfull to know type & number of cells or batteries in series. A regulator, V or I is required. Might read up on batteries at: http://batteryuniversity.com
The output V can be varied by opening pin 5 with a switch, allowing panel V -2diode drops at output. Lowering frequency will also lower V. 'can not help with multisim, not in my vocabulary.