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Powering a radio with solar cells

8bit

Oct 30, 2013
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I have a very small radio that takes two AAA batteries and runs on a total of 3volts. I would like to add a solar cell to it so I can run it without batteries. I am just a little confused as how to connect it to the power connecters at the back. The back of the radio is shown below.


radio_zps5lyprqaq.jpg
 

davenn

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Sep 5, 2009
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hi ya

the negative from the panel goes to the spiral terminal on the lower left
the positive from the panel goes to the terminal that cant be seen just above the lower left terminal

NOTE you will need a panel that can produce around 4 - 4.5V as it will drop to around 3V when under load

MOST panels voltage rating is an open circuit voltage rating. Confirm the O.C. voltage before you buy the panel


Dave
 

8bit

Oct 30, 2013
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Ah, thank you for clearing that up. I have a 3v solar cell and just no matter how I wired it I could not get any power in the radio. :)
 

davenn

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Ah, thank you for clearing that up. I have a 3v solar cell and just no matter how I wired it I could not get any power in the radio. :)

is that 3V open circuit ?

measure the voltage with the radio as a load once wired to the radio correctly
you may find the voltage is dropping to 2V or less ( you may need 2 cells in series)

Dave
 

8bit

Oct 30, 2013
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is that 3V open circuit ?

measure the voltage with the radio as a load once wired to the radio correctly
you may find the voltage is dropping to 2V or less ( you may need 2 cells in series)

Dave


That's the voltage across just the solar panel on it's own.
 

davenn

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OK then it will drop substantially when a load is applied maybe as low as 1V, so you may need 2 or 3 in series
 

8bit

Oct 30, 2013
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OK then it will drop substantially when a load is applied maybe as low as 1V, so you may need 2 or 3 in series


Thanks Dave, I'll try and pick up a couple more. Thanks for the information. :)
 
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