On Tue, 17 Jul 2001 07:08:35 -0700, you wrote:

>Find a wall wart with a regulated 5V output and then use a boost =
convertor to
>get your LCD display voltage.
=46or most small LCDs, you can often use a simple charge pump (cheaper!)
>
>"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.

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