Challenge: Find the circuit flaw?

[killivolt]

I'm assuming Rvs is connected to CC; I would like to see a diagram in LTSpice of course with a corresponding voltage and current chart; only if "Mike" is willing?

I'm really enjoying the "Thread"

"A case of the Mysteriously missing Regulator Voltage"

Perfect, October pre-halloween "Thread"

Well done.

kv

 

[tvtech]

I love this stuff

The LM317T....been around for yonks. Burned my fingers way ago when building a circuit from the "Art of Electronics"

Anyway, the venerable little 317 is basically in it's own right indestructible. I honestly can say that in all my years of fixing things besides TV's, they do not fail.
Every UPS I have seen (the ones with a 7.2aH battery) uses them as the main charging IC for the battery. And they normally mount the little LM317T on a small mickey mouse heatsink that gets as hot as hell when charging the flat battery...

Funnily enough..the other stuff fails before the little 317 does. If ever it even does.

Back to the LM317T. In an "ideal world" best Voltage Regulation practice would be to solder the little (I use 180 Ohms) directly between the adj and vout terminals. And then thick wires after that....don't want losses between them.

Hard on a PCB...but do able.

Gotta go and eat and stuff.

Regards,
tvtech

 

[MrAl]

Hi again,


killivolt:
Yes, ha ha, that's a funny idea, just in time for Halloweenie where we have the 'Ghost" voltage of 0.2 volts

tvtech:
That's one of the things like about the LM317, it's like a workhorse part that we only see once per million parts or something.
We can talk about that overheating problem too at some point. Luckily, the LM317 has built in protection maybe that's why you dont see any fail. If every part was like that we'd have it made


Now on to the next challenge which may turn out to be even more interesting than this one...but again with the illustrious LM317