why do you optoisolate

[louie]

Do you really only use electrical isolation between logic level control signals and the drive circuits (ie. dc-dc converter). Is the main reason for this because different voltage supplies are used (example: +/- 15 V for logic and 30 V for drive circuitry) and each has it's own reference to ground, so you don't want to short anything out.

Can someone please explain this a little better to me

Thanks

[chroot]

Opto-isolation is used whenever you don't want current from one part of a circuit to flow through another part of the circuit. It's mainly used when you have a portion of a circuit which uses large voltages, and another which uses low voltages. It can also be used to provide a "floating ground," so that two parts of a circuit can be grounded independently, yet still communicate.

- Warren