Emulating a throttle

[A_edwill]

Looking for a circuit for linear voltage isolation. I am running 0 - 4.7vdc output from an Arduino board via a DAC. Output must be linearly transferred to a motor controller which has its own 5vdc supply and ground. http://www.monsterscooterparts.com/24v- ... oller.html. Basically I am trying to imitate a throttle. Tried an H11F1 circuit, was able to create an isolated linear voltage circuit but it fails when hooking up to the 3 wire throttle sensor wires on the controller.

[pebe]

I don't know what you mean by 'linear voltage isolation'. The output from your DAC is an analogue voltage. You can only isolate (from DC) an AC waveform, so what exactly is the type of voltage you wish to transfer? Or are you intending to use a pulse of variable amplitude and want a circuit for it?