Take a look at the voltage booster in this device. http://www.uoguelph.ca/~antoon/gadgets/carnc12.htm I stumbled onto this from another post on the piclist... John Ferrell 6241 Phillippi Rd Julian NC 27283 Phone: (336)685-9606 Dixie Competition Products NSRCA 479 AMA 4190 W8CCW "My Competition is Not My Enemy" ----- Original Message ----- From: "Robert E. Griffith" To: Sent: Tuesday, July 17, 2001 11:08 AM Subject: Re: [EE]:Voltage Reg vs Switcher > Thanks everyone for the quick and informative responses! > > I am going to research both the split transformer solution and the 5-12 > voltage booster solution today. $10 is too much for a switcher in this > application. The budget is more like $4 or under. > > --BobG > > > > > -----Original Message----- > From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On > Behalf Of Mark Newland > Sent: Tuesday, July 17, 2001 10:09 AM > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: [EE]:Voltage Reg vs Switcher > > Find a wall wart with a regulated 5V output and then use a boost convertor > to > get your LCD display voltage. > > "Robert E. Griffith" wrote: > > > I have a design that uses a 12v wall wart power supply because an LCD > needs > > the 12v. The main circuit runs on 5v and 3v. In the prototype I have a > 5v > > regulator (LM340TS) dropping the 12v to 5v and a 3v regulator (TPS7230QP) > > that drops 5v down to 3v. This device will be on all the time. > > > > I have a heat sink on the 5v reg and it gets hot. I want to put the > finished > > circuit in a project box with vents but no fan. > > > > My question is: is there an easy, low cost, solution to implementing a > > switcher to drop the 12v to 5v? Is this done? The 3v reg does not provide > > much power so it is not a problem. > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics