owwww.
those lil 4wire RR units, as common on scooters, pitbikes etc...that is the weirdest description of how they work ive read, yet!
ac goes in via two wires, white and yellow.
dc comes out via the other two wires, black and red.
black is universal earth.
the battery is for starter motors, horns, etc.
lights run on AC happily. small bikes use current limited generators, that will produce a fairly constant power output despite changing rpm. they will always dim at idle to a certain degree.
some run lights from the battery, some dont. that lil RR unit is still common to em all!
the regulator requires a minimum of 4 volts more than its regulated output to regulate.
the ac supplied to the rectifier should be at least 20 volts. this is rectified to dc, then regulated to the standard 14.4 volts for charging lead acid batteries.
most bottle dynamos, in my experience, produce 6volts AC... maybe things have changed since then?
but. they are a current limited generator. they are designed to only produce so many volts at such a current at all rpm above a certain lower limit. this is to do with magnet strength, armature core thickness, and number of windings. they produce so much current, then there simply isnt enough magnetic field to produce anymore, no matter how fast you spin them. they wont produce any more WATTS than they are rated for.
only complete reenginering will fix them. change the magnets to windings and pump some current in there!
(interesting to stick a large neo on the casing in certain spots)
anyway, the standard 6vac ...that rectifies to about 7.2 volts DC... which quickly drops when any load is placed on the output... but ok for a 6v SLA.
you could try making a voltage doubler, which lowers the current available again...
regulators. one is a shunt type, one is switched.
the shunt has a standard bridge rectifier, delivering a standard DC voltage. that DC is regulated to a fixed voltage, while excess power is dumped into a "shunt" resistor, producing heat.
the bigger a load you run, the less heat they produce. brilliant
cheap, common, effective.
a switched regulator uses a bridge rectifier made from FETs. normally, nothings on, theres no output at all. the FETs simply are switched on when required. as soon as the voltage/current reaches required level, FET is switched off again.
its called "pulse width modulation" or "duty cycle regulation" depending on the system.
voltage through an "open" circuit from generator doesnt produce heat.
there is no "dumping" of excess power.
unit runs cool to touch, despite change of load.
expensive
for what you guys are doing, a simple diode bridge, and a 7812 regulator, good for 1 amp...
