Damn! Whilst I've been writing "War &Peace" HF has posted the above....well, buggrit, it may be of interest/use to someone. meanwhile, unless discrete components have been used, a solid- state reg is normally a throwaway. There are plenty on the aftermarket, but some adaptation may be needed. start with Durite and Wood-Auto. major suppliers of parts for rotating electrics (starters, alties and dynamos)
see below... as long as it's big enough to feed the required field and has the right connections, it's just a case of mounting.....of course, you could always rewire the whole generator circuit
Making a sweeping assumption that you're talking about a mechanical reg. as opposed to Solid- State. Also makes a difference if it's for a Dynamo or an Alternator. .
If you consider an Alty to be , basically, an inside- out Dynamo, understanding the basics becomes easier.
Breaking a magnetic flux with a coil, induces a voltage within the coil (you generate electricity)
We'll assume you have an alternator.....they're lighter, simpler and easier to make and give an increased output at low RPM. As they're superior to a Dynamo setup a premium-price can be charged. I nave never seen a Western-built Alty, with a mechanical reg. but plenty of Asian ones.
The Stator is the laminated steel body ,it has a series of "posts" projecting towards the centre of the cylinder, these have coils wound upon them, which are usually linked in series sets each set terminating in an output wire. Down the middle of this ring of coils, goes the iron Rotor which has a coil wound on it, terminating in 2 copper slip-rings . Carbon brushes contact these rings and fie a field-current to the rotor, which then becomes magnetised.
THE REGULATOR CONTROLS THIS FIELD. As the rotor spins, it's now-magnetised poles pass over the ends of the coils on the stator....you get output!
Initially, the voltage from the field is from the battery, via the reg. Some designs switch the warning-lamp, some have the warning-lamp in series with the field, thus, when you switch on, the current flows through the bulb, through the rotor windings (through the Reg, either before the field, or after)...then to ground.....the bulb lights and the field is weakly energised. as the revs build, the voltage rises Some designs, the output feeds back down the bulb, opposing the battery voltage feeding it. This, of course,slows the current flow, the light gets dimmer and when the battery and output voltages are equal, the current stops completely and the lamp(which has already gone out!)has equal voltage on both terminals. Other designs use the Reg to switch the lamp...Why? dunno!
To me, a self-contained, solid-state Reg is the way forward Warning-lamp and output terminal being the only 2 connections to the alty. (output is via a bridge-rectifier so you get "lumpy" DC out.....battery can be permanently connected to the output, as the rectifier acts as a one-way valve. If it goes faulty, it can drain the battery or alternatively, a phase -output is absent, so the output voltage drops.... insufficient to charge the battery,but often enough to sustain a small load.
Back to the Reg!. These are usually 2 or 3 solenoid coils. the armatures carry contacts. There are various resistors incorporated (these are often "hidden" and can burn out) and often the design incorporates temperature compensation. Basically, it switches the warning-lamp and supplies field-current to the generator. When output-voltage rises to a preset value (a bit over 14V for a 12V system), the regulator switches (via the solenoid coils) the field off...output ceases, regulator switches field in again cycle repeats at a very rapid rate. Also, of course, it switches the output to the battery, until it "sees" a fully -charged battery.
Above is by no means a full description! It should give an inkling of the complexity of a separate-reg. setup and the potential fault -paths.
A bit of searching should unearth the Lucas Voltage Regulator repair workshop procedures manual. The basic principles are the same and the explanations probably somewhat more ordered and concise than mine! Google is your friend!
Note that coils can be rewound, wire-wound resistors substituted, even burnt- out points can be replaced, The biggest problem for the unskilled, is setting -up the various coil-operating parameters. They have to be "tweaked" in a set order, within a set time-frame, or the generator has to be run at a set speed for a defined period before re-trying the procedure (minutes, not hours, but still a toil).
One is tempted to ask, "why not just buy a new one from China?".....It'll probably be as cheap as chips, ready set- up and OE quality (OK forget that bit) fit and forget.
Forgot to say, terminals are usually marked "D" (dynamo) or G (generator) or A (alternator) F- (field) B- (battery) WL -(warning-lamp) E - (Earth)
"suitably- qualified" Is someone who can make it work properly! that is self-evident.....if theyre not "qualified" they won't be able to repair it. "holds a suitable qualification " is another thing altogether!
When refurbishing a house, my late friend, a Chartered Engineer , dismissed the requirement for "suitably qualified" gas and electricity installers. He was variously in charge of gas, goal, oil and nuclear power stations and thus , far better qualified than the average fitter (but vastly less experienced, which is why I did most of it, being a man on the tools with no qualifications at all! )
hth.
FLYER Club Member
Worth checking first...
