:) Try it and learn. It's great exercise. :)
When you touch the heatsink of that TO3 after full-fielding it for fifteen minutes - instant lesson about vsat. When you compare output potential of a vsat slumped field voltage to direct full-field you will learn about ohms law and what 1.0 volt of field voltage loss due to a fully saturated device and how it degrades ouput. MOSFET transistors are not used in today's voltage regulators for the fun of it.
Yes the Author's design will work. No, it will not field an alternator anywhere close to the wattage available with today's MOSFETs. There is little transient voltage protection in the design except for the diodes. Shoot with that design why not advance a decade and utilize a Darlington power transistor? Do that and you'll jump up to 1980's technology.
Building stuff is fun. But not at the expense of ending up with something that is akin to strapping a sundial on your wrist. There are lots of modern A and B field voltage regulators on the market with external sense leads. A 1116387 Delco reg strapped to a good heatsink with heat sink thermal grease and protected by some 18 volt TVS diodes is a beautifully small package A circuit not B circuit reg that matches the design of MoPar field circuit operation. A MOSFET reg controllable with a one watt pot 500 ohms. Mounting this critter to a heat sink in a project box will make it infinetely mpre durable than a similar regulator mounted inside a Delco alternator. The added TVS protection is great. If you wish caterpillar bulldozer grade transient voltage protection substitute Motorola MR2535 avalanche diodes.
Discrete regulators have their place. A properly designed discrete VR can be a reality with today's MOSFETS. Housed in a waterproof NEMA box circumvavigation grade voltage regulators are a reality. I built a total of four in the 1990's. All had ohmite 30 ohm 7-amp rated power rheostats (remote) for equalization and bet-your-life dependability. Open ocean cruising is a whole different world. I've lost track of three of the four units. Black Swan is still going after 23-years. Last I heard she was in the Aegean Sea. She changed to Lifeline batteries around eight years ago. She is running a 3825 Leece Nevillealternator with one of my remote rectifier bridges - six 300 amp 1, 625 PIV rectifiers. The monster is bound to outlast it's creator :(
But do build the linked regulator. It's a blast to play with!
