# double the voltage half the amps...

Discussion in 'General Electronics Discussion' started by whilburn, Oct 25, 2011.

1. ### whilburn

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Oct 25, 2011
I found some solar cells online that produce 2.5 volts and 1 amp. I dont have any issues using multiple voltage regulators to utilize a regulated 5 or 12 volt output with almost any associated current requirement, but ive never been in a situation where current available is more excessive than the voltage available.
is there a boss type circuit that will allow you to double the voltage input and half the current output.
I would like to create a 5 volt 500millamp power source out of a 2.5 volt 1 amp available source.
Thanks

2. ### davennModerator

13,674
1,892
Sep 5, 2009
Hi
Welcome to the forums

thats ok just series 2 of the cells it will give you twice the voltage at the same 1 A current (2.5V + 2.5V = 5V)
keep in mind ( as you havent told us) that 2.5V may be an open circuit voltage and may be somewhat less under load, you may need 3 cells in series to get your steady 5V out

Have you got a link to them ? would be interesting to read up

cheers
Dave

3. ### whilburn

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Oct 25, 2011
Thanks for the welcome and thanks for the reply.
I found the originals on Amazon, but i found something just as well at the following:
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2140390_-1
For instance, this cell is rated at .5 volts and 2.5 watts.
At a previous employment, I purchased from Jameco on a regular basis. They have reasonable prices.
Back to the topic..
You did bring up a point I hadnt considered; efficiency of the solar cell to produce consistantly under a load compare to open circuit measurements.
I had considered serial/parallel connections, but i wanted to explore all possibilities. Hence, i still am interested in what would be required, circuit-wise, to provide a higher voltage output, but taking a loss on the current; assuming that we are dealing with a stable, regulated power source, and not a solar cell.
I realize that sometimes, especially in electronics, it may cost more than its worth
Ive looked at voltage doublers and dc to dc converters, but would like some advice.
Thanks.
Wayne

4. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,419
2,790
Jan 21, 2010
In general, the best approach is to use a maximum power point tracking (MPPT) regulator to charge batteries from the panels, and then to use another regulator to get your required voltage from the battery.

That may not be the best approach for you though

The main problem with solar panels is that you get no power when the sun isn't shining, and much reduced power with cloud cover. If you don't have a battery to hold the charge, you will have to ensure that occasionally losing power (more likely getting a low voltage) is not going to cause problems.

5. ### Externet

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Aug 24, 2009
Get another cell of those and connect it in series; will double the voltage.

6. ### whilburn

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Oct 25, 2011
Ok, I realize this post turned into a Solar Cell discussion, but as to my original question, is there an existing boss chip, or is there a known circuit combination, so named, that, at the cost of current, can boost the voltage, yet still supply levels of current higher(hence the Half the voltage, twice the current..) than those rated for typical OP amp or IC levels?

BTW, I have in posession from Radio Shack, 9 of the following cells (Thats buying out the cells from 3 stores )
Radio Shack Part number : 276-0124
I will be playing around with these, knowing i will have to add more. But let the experiments begin....

7. ### davennModerator

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1,892
Sep 5, 2009
yes there are "buck converters" these are DC -DC voltage regulators

have a look in google using that description

cheers
Dave

8. ### BobK

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Jan 5, 2010
Actually it is a boost converter that he is looking for. A buck converter lowers voltage.

Bob

9. ### davennModerator

13,674
1,892
Sep 5, 2009
too early in morning yes boost converter

here's an ideal one for you

Dave

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Last edited: Oct 27, 2011
10. ### whilburn

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Oct 25, 2011
Thanks for all the info, i just havent had time to "play". My daughter's high school band competitions have been keeping me busy. They won a huge competition and are now going to compete at the Nationals in Annapolis Maryland. Not that im proud or anything,... but i wanted to express my thanks for the help on this forum.

11. ### foTONICS

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Sep 30, 2011
stepping up the voltage through a 1:2 transformer will double your voltage and half your current

12. ### Resqueline

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Jul 31, 2009
The OP was referring to DC, in case you didn't notice... I would consider it a useful reply if you came up with a suitable circuit that would be needed around the transformer..