12V Regulator Max Input...

[NC Cams]

The LM2940 comment was made NOT to have it be used to go from 36 to 12 BUT rather to get away from the time worn and mundane 7805 and 7812's.

These were great in their day but 2940's are far superiour in what they offer to the DIy'er, especialy those who use battery and other places where LDO or noisey bus and signals can occur. In fact, with situations where there are a lot of relays or other electyrically noisey disturbances, the 2940 can save you from a lot of problems - especially with servo dumping and voltage spikes.

Thank god for wall bugs. KISS metod if there ever was one.....

[Eclipze]

Originally Posted by NC Cams The LM2940 comment was made NOT to have it be Thank god for wall bugs. KISS metod if there ever was one.....

Hahaa... yeah, but it still bugs the crap out of me (being an electronic engineer) that even with wholesale pricing, I can't make one as cheap as a $10 wall adaptor... yet they make a profit on it!

[NC Cams]

I think it has something to do with the black helicopter consppiracy.

That's what the voices I keep hearing tell me....

Never mind, they just quit......

[Al_The_Man]

Originally Posted by Eclipze Hahaa... yeah, but it still bugs the crap out of me (being an electronic engineer) that even with wholesale pricing, I can't make one as cheap as a $10 wall adaptor... yet they make a profit on it!

The thing to watch though with wall warts is that the vast majority, especially the cheap ones are unregulated, they rely on the rated load to bring the voltage down.
Just check the open circuit voltage.
They are simply a small txfr, bridge and Cap.
Al.

[Eclipze]

Yes... your quite right about the regulator not being accurate. I always go for the lightweight switchmode designs, which run cool and aren't a big heavy things hanging off the wall hogging two spots. I've found them more accurate, but for electronics on 5V I still prefer to put my own regulator in, such as a LM317 with heatsink. If I draw a lot of current, I use something like a 7.5 or 9VDC adator into the regulator, which keeps a good supply to the regulator without excessive heat.