Now I'll have to source some PIN diodes and try again after Warren's comments. The phase sensing idea is pretty cute. I'll have to think about that too.
Thanks again
Steve
Thanks Warren
Thanks for the reminder Warren - I used what I had, but when I get my hands on some PIN photodiodes, I'll try again. Any suggestions for sources of 'em ?
Steve
Dumb idea.
Well, for future reference that was a very dumb idea. There is no power available at all. With three yellow diodes in series, there is quite respectable voltage (4V ), but the output impedance is in the order of 100s of KiloOhms.
Transformer coupling, here we come.
Still, I might...
Thanks for comments so far
Thanks for all your comments so far - maximum shaft speed is 0.3 RPM, so direct generation is not a go-er.
The trouble with laser sources is the beam is very small and that makes coupling the light to the pickups very difficult. My current thought is to use the...
Numbers
Having "googled" into this thread, I was hoping you could help with my own "LED lighting" question. I have a cost-sensitive instrument application where I need to supply roughly 50mW to an assembly rotating on a motor shaft, about 6mm from the nearest support.
I wondered if I could...