EMRFD Message Archive 5398

Message Date From Subject
5398 2010-11-08 13:01:50 Robert Cerreto KA7EXM Power Meter Reality Check
I need a reality check,

I am building a derivation of Roger Hayward's power meter. Roger used LM324 OP AMPS for some DC conditioning. I do not have any of those on hand, but, I do have some LM2902's . Looking at the data sheets and circuit topology, there does not seem to be any reason why the '2902's cannot be used.

Have I missed something?


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5400 2010-11-08 21:05:44 ka7exm Re: KA7EXM Power Meter Reality Check
Hi Bob.

Yep, the op amps are there just for voltage scaling. The PIC processor reads the voltages once every 100mS or so (if I remember correctly). There's no fancy time scaling or high speed sampling, etc. So any pin-compatible voltage scaling would work just fine.