[sdiy] LM 317 regulators

[oleavitt at ix.netcom.com]

I have a multi-output bench power supply that I built about 20 years ago using an LM317 and a few other 78xx, 79xx regulators for fixed outputs.
It still works like new.
I have had no instances of failures or malfunctioning with 3-terminal regulators in that time. Then again, I don't use them that much - perfering LM723 based regulators for critical applications.

The ICs are mounted on an oversized heatsink and have never gotten hot. The unregulated voltage input to the ICs is about 30 volts from ground to the IC's input.
  
Generally, keeping semiconductors (and other parts) cool, free of dust/debris/contamination, and running them well within their rated maximums contributes to long life and reliabilty.

On Fri, 22 Mar 2002 11:07:43 -0800 greg montalbano <greg.montalbano at ucop.edu> wrote:

Hello --
I would be curious to hear people's experience with LM 317 adjustable 
regulators -- specifically, instances of intermittent fault or breakdown in
parts approaching the 20 year mark.

Thanks, eh?

~GMM