I usually don't do half-solutions. More time would be wasted if the need suddenly arises for a project, and then I would have to go back to working on a power supply instead of the project itself.

No serious hobbyist has just one power supply.

 

The '337 provides a regulated negative voltage supply for IC1. This is needed if the supply is to be adjustable down to zero volts.

 

No serious hobbyist has just one power supply.

I still don't see the benefit of skipping features for this particular project.

The '337 provides a regulated negative voltage supply for IC1. This is needed if the supply is to be adjustable down to zero volts.

Ah that makes sense, thank you! It's a great idea and simple enough to implement into my own design.

 

The LM337 IC4 negative regulator is supplied by diode-pump C2, D5, D6 and provides approx -3VDC negative supply to the TL082, - to include 0VDC within their input common-mode voltage range. Unclear why 2 reference Zeners used when single 6.2 or 6.8V Zener (depending on current) would give optimum near-zero voltage/temperature coefficient. Seems a shame to be using Zener refs when there are two high-quality references (IC1, IC4) already on board.

The base drive available (through R14) to the BD139+2N3055 is probably inadequate. Q1 may have been added to cover a switch-on condition and/or a rather uncertain (and very temperature-sensitive) max current limit action; not too healthy that it directly pulls down IC1B output.

Current sense resistor R7 runs at 3W max; 0.05ohm (with Kelvin sense connections) would be more normal (0.5W) with amplifier offset removed by preset potentiometer.

The circuit does look as though it could basically work but the designer was probably unaware of the possible simplifications obtainable through providing separate low-power auxiliary supplies for the control circuitry.

 

The LM337 IC4 negative regulator is supplied by diode-pump C2, D5, D6 and provides approx -3VDC negative supply to the TL082, - to include 0VDC within their input common-mode voltage range. Unclear why 2 reference Zeners used when single 6.2 or 6.8V Zener (depending on current) would give optimum near-zero voltage/temperature coefficient. Seems a shame to be using Zener refs when there are two high-quality references (IC1, IC4) already on board.

The base drive available (through R14) to the BD139+2N3055 is probably inadequate. Q1 may have been added to cover a switch-on condition and/or a rather uncertain (and very temperature-sensitive) max current limit action; not too healthy that it directly pulls down IC1B output.

Current sense resistor R7 runs at 3W max; 0.05ohm (with Kelvin sense connections) would be more normal (0.5W) with amplifier offset removed by preset potentiometer.

The circuit does look as though it could basically work but the designer was probably unaware of the possible simplifications obtainable through providing separate low-power auxiliary supplies for the control circuitry.

Your comment is very insightful, thanks!

I will duplicate this circuit in my simulation and see what I can do regarding the improvements you mentioned.

If the circuit simulates as expected, we can hopefully discuss possible simplifications and improvements - I already have some on my mind.