Thanks Jim - as ever I appreciate your response. Don't suppose you can lay your hands on that "typical circuitry" for firing the torch from TTL. I know I can just wack in a relay but with such a low V and A I'm thinking it's perhaps a bit overkill - maybe not. As far as a SSR is concerned I'm sure I read somewhrere that they're not good at switching such low current - might of course be mistaken though - thoughts?
Cheers
Ian