<1VDC Regulator

The trick to getting a 0 to whatever voltage using a 317 is to have a negative voltage supply that serves as a reference point to the regulator in addition to the positive supply. I have used a couple for this, one fixed for the negative reference and the variable one driving pass transistors.

A cheaper trick is to simply add diodes (or a zener) to the ouput of the 317 (but it wont help is you are driving pass transistors for a high current output).

It works. I used that technique to produce a 0 to 100V DC 0 to 10A power supply, adjustable in steps of 10mV and current limit in steps of 10mA as my first degree project, more years ago than I would care to mention...

I suspect that you are getting your common references mixed up..

Try this: Model a standard dual (positive and negative rails) regulated supply. Say +15v, -5v. Now add an additional adjustable positive regulator that takes the +15v as input but uses the -5v rail as the common reference. Set its voltage to +5.1v wrt its reference, the -5v rail. You then have a +0.1v regulated supply, using the output of the adjustable regulator wrt the common reference of the +15v regulator..

Thanks Time and Sue,

I understand what you guys are saying. Now, I can definitely simulate and get the >

I couldn't find where in the article you read that. However, an offset zero reference works, irrespective of whether the offset is negative (for a positive output supply) or positive (for a negative output supply. Where one has a dual regulator, producing both positive and negative output voltages, the offset reference is automatically included "at no extra cost".

Another neat little trick is to use a high power bridge operational amplifier (or even some audio amplifiers) - these can be used to produce a dual output power supply where each output can be varied over a wide range of both positive and negative output voltages, plus achieve tracking "at no extra cost"..

I have heard of using a Crown DC series amps to charge car batteries in a pinch by applying a small battery voltage to the input.

I jump started a car once by rolling my bumper to the other car's bumper, and used a six foot scrap of solid aluminum clothesline wire between the positive terminals. Luckily, it started the first try. The wire was too hot to hold onto after that. :(