LM2575T-5 Switch mode 5pin TO220 package 7V-40V input and 5V @1A Output is
about £1.80 10off

LM2576-5  Switch mode 5pin TO220 package 7-40v input and 5V @3A Output is
about £2.10 10off

These devices need only two capacitors and one Zener diode.

Regards,

Jay


At 11:25 23/04/00 -0400, you wrote:
>Does anyone have a suggestion for a low cost low parts count 5V DC 1A
>power supply that will work with a 10-40V input.  I am looking to
>replace 7805 regulators in some designs I have that are in very small
>enclosures and don't have room for a heat sink.  A 7805 without a heat
>sink in a small case only driving 100mA will burn up in no time with a
>30V input because it has to dissipate 2.5W of heat.
>
>I am looking for a switching type regulator that costs no more than a
>few bucks and takes minimal board space.  Preferably no external parts
>other than an inductor and a cap.
>
>
>