"Eeyore" wrote in
message ...


Arfa Daily wrote:

"robb" wrote in message

so i tested by connecting 5V/1A DC source between Vin and
GND-Pin3 and i checked the voltage with DVM between Vout
and
GND-Pin3 and i was getting 3.47 V

Pointless. It won't operate correctly with only 5V in. 3.47V is
sort of what I'd
expect under those conditions. A linear voltage regulator has
to have several
volts more on the input than the output to function correctly.

hi graham,
just being cautious and i do not have much in the way of handy
power sources, various wall warts.


i changed to a 18 v/3.5A DC source and i was measuring
8.67 V
between Vout and GND-Pin3

L387 is cool and when i connected an LED load to Vout the
L387 got very hot
very quickly so i suppose i at least need to get an L387 ?

What value resistor did you have in series with the LED ?


you need to use a resistor ???

just joking it was 100 Ohm 1/2 watt (Brwn Blk Brwn Gold)

would you expect 8.67 Vout with 18V DC Vinput ?

thanks for help,
robb