That's right. If you follow the link to the example circuit that the OP sent there were some sizable caps on the output of the regulators. -------Original Message------- From: Jinx Sent: 08/15/03 07:03 PM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [EE:] 24vdc from a 15vdc psu > > > >There's an issue with linear regulators when the output voltage > >is higher than the input voltage. You might want to look at > >adding diodes around the linears to discharge the output caps. > > There's no "issue", they don't go there. > You can't get 24V output from 15V input, on a linear. I think he was referring to a shorted or lowered input when the output is seeing a charged filter cap. A diode from output to input will shunt the C charge away back to the input -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads