Posted by Gary Atkins on July 24, 2003, 9:10 am
I have a light activated switch circuit which uses 30ma during daylight.
Unfortunately this is way too much for the little 9V battery I want to use.
I want to keep this battery (max charge 25ma) charged up with a panel.
Rather than buy a new panel, I would like to use a 12V 250ma for the job.
Question is.....how do I adjust the voltage and limit the maximum current so
I don't fry the 9V battery?
Posted by JeroenH on July 24, 2003, 9:39 am
There are circuits on the net to limit current, but it's a rather
inefficient way, don't you agree? You could try it with a simple resistor,
but when resistance fluctuates in both the panel and the battery the
charging current will change accordingly.
It would be easier and probably cheaper to buy a simple thinfilm 25mA panel
and charge your battery with that.
You could also go with a bigger battery which can handle the 250mA charging
Posted by Gary Atkins on July 25, 2003, 9:30 am
Err....please explain ?