View single post by mikesndbs
 Posted: Apr 19th, 2011 05:38 AM
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Joined: Nov 21st, 2009
Location: United Kingdom
Posts: 182
Hi Ron and thanks.


We must have been thinking along similar lines.

I have just rushed through a number of tests.

OK, when I connect a speaker up the output is clear and fine.

I tried dropping the value of the resistor to 12 Ohms as the amp works between 4 and 16.

I tried red, green and yellow LEDs and I also tried a 2.2v torch bulb.


The distortion was about the same for all.

The best performance was from the BPX65 Silicon PIN Photodiode but only if I cupped my hand around it making a tunnel.

This put me in mind of a Opto isolator!

Lots more to try, laser microphones sound interesting as do the UV diodes.

But, is there any evidence for the vibration that spirit can best work with?

I had assumed IR.