Cookie wrote: Be careful disabling the main lights on a machine that normally has them on all the time. Unless I am mistaken, on many bikes the regulator just dumps excess current to earth giving off heat in the process. Without the lights on it will have to dump more power than it was intended too. If it can't get rid of the extra heat it could get damaged or its life shortened.

I may be wrong in this naturally

Not something that crossed my mind

I would have thought it would just be less load on the alternator

I'll look into it

My understanding is that scooters and smallish bikes have a basic charging system. In this the alternators output is fixed although dependant on the engine revs.
The regulator allows 'x' amount through depending on the demand of the bikes electrics. The remainder it dumps to earth. This generates heat so the regulator has some cooling fins usually and some heat can be absorbed via the mounting bolt to the frame.

The less power the bike is using the more has to be dumped and the more heat is produced. If the bike was designed to have the lights on all the time the manufacturer may have reduced the fins or cooling area accordingly.

Hi end bikes and cars have more advanced alternators with variable excitation rather than permanent magnets so their output can be adjusted according to demand.

No doubt someone vastly more clued up than me will be along soon with more reliable info
It's worth checking into though.
Cookie

Cookie wrote:My understanding is that scooters and smallish bikes have a basic charging system. In this the alternators output is fixed although dependant on the engine revs.
The regulator allows 'x' amount through depending on the demand of the bikes electrics. The remainder it dumps to earth. This generates heat so the regulator has some cooling fins usually and some heat can be absorbed via the mounting bolt to the frame.

The less power the bike is using the more has to be dumped and the more heat is produced. If the bike was designed to have the lights on all the time the manufacturer may have reduced the fins or cooling area accordingly.

Hi end bikes and cars have more advanced alternators with variable excitation rather than permanent magnets so their output can be adjusted according to demand.

No doubt someone vastly more clued up than me will be along soon with more reliable info
It's worth checking into though.
Cookie

A "basic" regulator can simply be 4 diodes configured in the bridge layout - ac goes in, dc comes out

It's necessary to have some form of voltage limiting - before alternators, it used to be solenoids that cut in and out as the voltage increased and decreased - but alternators have built in solid state voltage regulation

I think scooters and motorcycles are kind of hybrid - I don't think it's quite an alternator, so you may be right that the stator produces a voltage and current dependent on engine rpm, and the regulator changes it into a controlled voltage

I would have thought that the electronics in a regulator would control things - i.e. not waste energy by turning it into heat - and the heat sink being there to stop the regulator electronics being destroyed by the heat the regulator creates as it does its work - the same way that a power transistor uses a heat sink to dissipate heat it creates - it would otherwise destroy itself in a few milliseconds

I'm clued up on electronics, but I'm not sure how primitive scooter and motorcycle regulators are

I suppose an alternator has to be reasonably large to be efficient, otherwise we'd have small ones on motorcycles and scooters

Ive done a quick check on the Internet, and what I think we have on modern motorcycles and scooters is an alternator - but it's not a self-contained unit like on a car - we have an alternator consisting of 2 parts - a stator and a regulator

Alternator has two working parts, the stator is the part that's static, the other bit is the rotor which rotates.
These generate an ac output which the rectifier turns into dc and the regulator keeps between the desired voltages.

gn2 wrote:Alternator has two working parts, the stator is the part that's static, the other bit is the rotor which rotates.
These generate an ac output which the rectifier turns into dc and the regulator keeps between the desired voltages.

Yes, motorcycles and scooters have a stator - a series of copper wire coils - being the part that usually burns out (notoriously quickly on some new motorcycles)

There will also be a magnet rotor that generates electrical energy in the stator

I suppose the two together are an alternator - because alternating current is produced - just that a regulator is not included - it's an external device

Another video, nothing really new, just a compilation of photographs with text and a minor service.

great vid well done... i removed the seat the the battery box for spark plug access not sure if easier, up to you lad... oil change for me this weekend