Hi there,
I'd like to count pulses from the LED on my electricity meter. Pretty easy if I had a good power supply but I want to run on a coin cell battery. The tricky bit is I can't find a photo diode with a lower enough power consumption. I'm trying to work with a budget of 10-20uA (aiming for more than a year battery life). Lowest photo-diode I can find is 800uA which isn't going to work for me.
So I had the idea to use a photovoltaic light detector instead. ie. Use a sensor that converts the LED output into a tiny DC current without draining the battery.
Is this going to be possible? Does an LED emit enough light to activate a photovoltaic cell? If I could find a photo-cell that could register a LED pulse then I'd feed those pulses into an PIC interrupt and that would be my counter.
Any pointers appreciated.
Cheers,
D.
I'd like to count pulses from the LED on my electricity meter. Pretty easy if I had a good power supply but I want to run on a coin cell battery. The tricky bit is I can't find a photo diode with a lower enough power consumption. I'm trying to work with a budget of 10-20uA (aiming for more than a year battery life). Lowest photo-diode I can find is 800uA which isn't going to work for me.
So I had the idea to use a photovoltaic light detector instead. ie. Use a sensor that converts the LED output into a tiny DC current without draining the battery.
Is this going to be possible? Does an LED emit enough light to activate a photovoltaic cell? If I could find a photo-cell that could register a LED pulse then I'd feed those pulses into an PIC interrupt and that would be my counter.
Any pointers appreciated.
Cheers,
D.