Russell McMahon wrote: > An appropriate small N Channel MOSFET would work with ease as the > voltage gain is close to infinite for practical purposes. You want... I think you intended to say "current gain is close to infinite..." :-) MOSFET requires essentially a voltage at the Gate to turn it on, insignificant DC input current causes significant DC output current flow (Drain - Source). -- Brent Brown, Electronic Design Solutions 16 English Street, St Andrews, Hamilton 3200, New Zealand Ph: +64 7 849 0069 Fax: +64 7 849 0071 Cell: 027 433 4069 eMail: brent.brown@clear.net.nz -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist