Hi Darren, Agilent has some opto devices which can be used to detect a primairy voltage, AC and/or DC. It also gives you a galvanic isolation. Maybe you can use it to control a relay, which default points to the DC voltage. When an AC voltage is detected, it will switch the relay, selecting the other source.
Kind regards, Elbert. > -----Original Message----- > From: Darren Logan [mailto:[EMAIL PROTECTED] > Sent: donderdag 18 december 2003 10:54 > To: Multiple recipients of list CHIPDIR-L > Subject: Auto AC/DC select power supply > > > Hello, > > Does anybody have any idea how one can go about designing a > power supply which can run from AC mains or DC - > automatically switching itself for either input. For example > 90-260V AC and 8 to 24V DC (output 12V, 1A)? > > I guess there will be some kind of front end detection > circuit (of AC or DC) which controls how the input is converted. > > Best regards > Darren Logan BSc(Hons) > Development Engineer > ________________________________________________________________ > MICHELL INSTRUMENTS LTD Tel: +44 (0)1223 434 854 > Nuffield Close Fax: +44 (0)1223 434 895 > Cambridge e-mail: [EMAIL PROTECTED] > CB4 1SS, UK web: www.michell-instruments.com > UKAS accredited: 0179 * ISO9002 accredited: Q6284 * Member > BCAS * Investor in People > --------------------------------- Dew point specialists > --------------------------------- > This communication contains information which is confidential > and may also be privileged. It > is for the exclusive use of the intended recipient(s). If you > are not the intended recipient(s), > please note that any distribution, copying or use of this > communication or the information in > it is strictly prohibited. If you have received this > communication in error, please notify the > sender immediately and then destroy any copies of it. > > > -- > Author: Darren Logan > 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). > -- Author: Elbert Smit 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).
