Thanks for the information. The meter has a red LED and I'm struggling to find photo-transistors that aren't specifically for infrared. Will an infrared one work? Also how does the two-pin phototransistors differ from the 3 pin ones?
gardner:
GoForSmoke:
put a transistor out there with the LDR for more 'contrast'.Or better yet, use a photo-transistor.
This is the circuit I used to count the pulses from my power meter.
power monitor « Projects