GearHeads Corner

tweakie wrote: I appreciate that the operation of my signal inverter circuit is perhaps not easily understood so I have attached a diagram.
(It was done this way so that it could be used in circuit with the ribbon cable and not require an additional power source).

Tweakie.

If you remember i has the same problem on my laser source , some residual voltage without connection , and very low impedance , like 60R . Strange chinese source
and i fix it with a specialised DAC and op-amp to force the source down to 0 without change my square wave . You schematic was my first try but the power wasn't lineary .
error of my stupid source + transistor error + optocupler error for me was not working i expected.
Unfortunately i didn't draw a schematic  :(

Thanks
Bobby