Detecting optical pulse from electricity meter

[AlanSlough1970]

Can anyone suggest a cheaper version of this product?...

just want to use a single-channel 0-2V datalogger to count the LED pulses from an energy meter.

I can use a soldering iron but I've no experience using photosensors

Thanks.

[Peter Scott]

I just found a kit on eBay for £2.75. Try 'light sensor kit'. It switches on an LED. You could replace the LED with a suitable relay from CPC or Rapid. This can then switch the 2V for the data logger. You get the 2V by using two resistors as a potential divider splitiing down the supply voltage for the sensor board. Tape the sensor to the meter when the sensitivity is correctly set.

Peter Scott

[Andy Dingley]

product?...

USB Bitwhacker is pretty good as a minimal USB IO interface for PC based logging your simplest option is probably some Maplin kit / loose bits and a bit of web searching for a basic electronics guide to op- amps and potential dividers. Just stick the photodiode in there between (series) a couple of suitable resistors and you'll get a voltage swing from it. A cheap op-amp IC on a slice of Veroboard will let you interface almost anything to almost anything else, voltage- wise, with just a handful of resistors (for sensible currents).

The minimalist might even use a photoresistors in a potential divider chain. Only two components...

[Bob Eager]

product?...