Scratch that idea
I connected the laser diode up with the audio transformer and first looked at the output on a scope. The usual low level mains was there but noticed that I was getting pulses when moving the laser around on my wood table,a copper coin or other metal objects. So I then hooked up an audio amplifier to the transformer and found out that the laser diode module acted like a microphone when handled and when I moved it across the copper penny it made quick narrow pulses over the raised shapes,ditto on my needle nose pliers with its tiny grooves from being polished.
I'm sure that Esteban discovered this early on and found the better method of modulating the Laser with a square wave.
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