I have a problem that has me stumped. I'm using an n-channel power mosfet as a source-follower pre-regulator to increase the input voltage range of a 5 volt regulator. That is, 50 volt supply to drain of FET, zener from gate to ground, resistor from gate to drain, source goes to input of 3-terminal 5 volt regulator, capacitors to ground from both source and drain of FET.
This works okay however my original design had a capacitor across the zener as well, and the FET oscillated at high frequency and got hot. Taking t he capacitor of the zener fixed that. But I stil lhave occasional blowups of the regulator, which I assume is to do with instability of this circuit. Have I done something stupid? Peter Vogel ZapTV Pty Ltd 30 Adeline St, Faulconbridge 2776 Australia Tel: 02 4751 8735 Fax: 02 4751 2601 email: [EMAIL PROTECTED] -- Author: Peter Vogel INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
