Rich, W3HWJ wrote:

See section 9.2 of the data sheet.

V out = Vref ( 1 + R2/R1)

Vref is 1.25 V

More instruction there on designing whatever voltage you want.

Rich

I saw that formula, but wasn't sure if I was doing the calculation right.

I found an online formula for a LM-317 and here's what I got.

For an 82 ohm R1 resistor I get a resistance of 6.8K for a voltage of +105Vdc and the input B+ will be around 120Vdc.

For an 82 ohm R1 resistor I get a resistance of

820 ohms for +13.75 volts

1K for +16.494 volts

1.5K for +24.116 Volts

B+ will be around 60Vdc

So I gotta figure out what voltage is best. I'm thinking the lower voltage as the 7805 on the clock board has no heatsink.

Now are those calculations correct?

In both instances the regulators will be mounted to the chassis using a transistor mounting kit to keep them isolated from the metal chassis while providing adequate heatsinking.

The first example the regulator is pretty much just a drop in as I already have the filter caps and rectifier.

The second one I am using a 1/2 wave rectified supply and 5600uF cap as the main filter cap.