Plotter Cutter Help

[(*steve*)]

I don't suppose you have access to an oscilloscope?

I suspect there is something that is reducing the duty cycle of the regulator to almost zero.

With the photos you've shown, I can't figure out how the optocoupler gets turned on only when the voltage hits the required value. Typically you'd have a zener diode or a TL431 in there somewhere. I can't see one.

 

[trev]

there's a TL431AA under the octocoupler..

 

[(*steve*)]

Aaagh! Perhaps some better photos are in order. (Please see here).

 

[trev]

sorry- night here at the mo but here's one to keep you going..

 

[trev]

any other ideas or do you need new pics? cheers