[b3lha]

Originally Posted by Calum

http://www.calumsult.com/calumsu/dis.../SVX/SSM_0.pdf

Thats what I would add. The ratio of R2 and R3 sets the low point of the comparator. With 10k and 6.2k its at approx 2V.

This looks exactly how I thought it would when you mentioned. Next time I go near the electronics shop I'll pick up the parts and give it a go.