View Single Post
Old 9th Sep 2019, 5:47 pm   #46
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Defective/ fake LM317T

As others have noted, you need a certain minimum current through the resistor-network; I've generally used a 5K variable, *and* a separate load-resistor from the +ve output to ground to place a consistent load on the chip.

The diodes and decoupling caps are highly recommended too!

[I've used loads of the TO3-cased LM117/LM317 3A-rated "Steel" regulators in the past and they behave well if treated well; I've also built quite a few little power-supplies using a Vellemann kit

http://www.velleman.co.uk/contents/e...198_k1823.html

based on the TO220 LM317 and they work just fine for powering Roberts radios like the 707 and 606].
G6Tanuki is offline