27-08-2017, 20:04
Hi jgveill,
When I read your first post, I did a interpretation mistake, which I only realized when I read your second post ("10 series cells giving an open circuit of 5 volts").
I understood that you are talking about grouping solar panels (which have many individual solar cells), instead of adding individual solar cells.
As I said before, the main problem I see, in trying to get a higher short circuit current, is the power dissipation on the shunt resistor and on the diodes itself. Ok, 0,23A on a 3 Ohm resistor causes a dissipated power of around 0.16 Watt, not a big deal for a 1/4 Watt resistor.
However the use of and OP, as referred by AllyCat in previous post, has some advantages, mainly for calibration, as its easier to deal with a potenciometer to change the OP gain, than making changes in the shunt resistor.
When I read your first post, I did a interpretation mistake, which I only realized when I read your second post ("10 series cells giving an open circuit of 5 volts").
I understood that you are talking about grouping solar panels (which have many individual solar cells), instead of adding individual solar cells.
As I said before, the main problem I see, in trying to get a higher short circuit current, is the power dissipation on the shunt resistor and on the diodes itself. Ok, 0,23A on a 3 Ohm resistor causes a dissipated power of around 0.16 Watt, not a big deal for a 1/4 Watt resistor.
However the use of and OP, as referred by AllyCat in previous post, has some advantages, mainly for calibration, as its easier to deal with a potenciometer to change the OP gain, than making changes in the shunt resistor.