Building a voltage regulator with a LM317T(update)

[Paul Perry (Frostwave)]

The likeliest thing is, the regulator sends out ripple when you ask it to supply a voltage that is less than 2 or so volts below the lowest part of the unregulated input (which of course varies over the mains cycle).

plus, as you add more fx to the load, the raw input voltage is sagging a bit. And to complicate things, the fx may not present a linear load to the unit, like add 10% to the regulator output voltage setting and the current drawn might be up 5%, or maybe 15%!!, not saying this is happening, but it could.

[RDV]

I just spent some time plugging in a bunch of rarely used boxes using my little Wart/Regulator contraption, running 3 of them at a time, and got good results across the board. I even got that Shoctave thing to behave and decide which octave it wants to generate. It's making everything I've got(20+ DIY circuits) all behave like they've got a nice fresh battery.

I'm getting braver so I think I'm going to start building supplies and forgoing the wall wart part. Any suggestions for good transformers 4 this?

RDV

[beans_amps]

Why the 1k sense resistor and 10k POT?  Is this jsut what you had on hand?  Do you need good low current (less than 5mA) regulation?   The 1K resistor will lower the max current drawn from the 317.  I can't  remember now what the correlation between the sense resistor value and the max current is.  Seems like a 1k will limit you to about 150mA.

Not a problem for a couple of effects, but if you have a large pedalboard, it could add up and cause a problem.

Sean Weatherford
Bean's Amp Repair
Central, SC

[RDV]

It was a tutorial on making a voltage regulator for a computer cooling fan. See Link above.

We all might be better off just using the datasheet circuit shown here.
http://www.national.com/ds/LM/LM117.pdf

I'm gonna do another one with these values tonight.

RDV