09-14-2018, 05:32 AM
"The CB1100 type, with its permanent magnets is so simple compared to the other two types that I think there must be some downside to it or why would they have gone to so much trouble to use electromagnets on the rotor?"
We've now come to the voltage regulator part of the electrical charging system, the task of this system is to provide 14 volts to the electrical system and the battery.
Once the bike is started the alternator starts charging the battery and supply energy to the on-board electrics like ecu, lights, injectors, fuel pump etc.
Initially the charging system needs to replenish the battery's energy used by starting the engine with the starter motor, so the alternator delivers more current until the battery is charged back up.
This is all controlled by the voltage regulator/rectifier and works in a similar way than a toilet cistern, it maintains ( regulates ) a constant level of water pressure ( electrical voltage ) whatever the usage ( current ) requires.
The technology has changed over the years and so have the alternators.
There were no powerful mosfet transistors in 1970, the technology used was a coil with a set of contacts (cb550) and a spring that was set to maintain 14 volts dc. and six diodes.
Later it became possible to use transistors instead of the coil and spring to regulate the 1 ampere or so to control the field wiring.
The last step happened when there were powerful mosfet transistors available that were capable of handling 40 amperes in a very efficient way called "pulse width modulation", in effect the same as the old coil and spring in the way it switched on and off but now in a very high frequency so it looked like dc.
So rather than control a field coil to behave like a magnet that can be controlled with variable current we could now control the output efficiently, no need for a complex field coil, it was replaced by more reliable and cheaper permanent magnets.
And so all the regulation and dc rectifiers are housed in one unit with three yellow wires going in and constant 14 volts dc from the two red and black wires leaving the small very efficient waterproof unit at up to 40 amps, simple.
We've now come to the voltage regulator part of the electrical charging system, the task of this system is to provide 14 volts to the electrical system and the battery.
Once the bike is started the alternator starts charging the battery and supply energy to the on-board electrics like ecu, lights, injectors, fuel pump etc.
Initially the charging system needs to replenish the battery's energy used by starting the engine with the starter motor, so the alternator delivers more current until the battery is charged back up.
This is all controlled by the voltage regulator/rectifier and works in a similar way than a toilet cistern, it maintains ( regulates ) a constant level of water pressure ( electrical voltage ) whatever the usage ( current ) requires.
The technology has changed over the years and so have the alternators.
There were no powerful mosfet transistors in 1970, the technology used was a coil with a set of contacts (cb550) and a spring that was set to maintain 14 volts dc. and six diodes.
Later it became possible to use transistors instead of the coil and spring to regulate the 1 ampere or so to control the field wiring.
The last step happened when there were powerful mosfet transistors available that were capable of handling 40 amperes in a very efficient way called "pulse width modulation", in effect the same as the old coil and spring in the way it switched on and off but now in a very high frequency so it looked like dc.
So rather than control a field coil to behave like a magnet that can be controlled with variable current we could now control the output efficiently, no need for a complex field coil, it was replaced by more reliable and cheaper permanent magnets.
And so all the regulation and dc rectifiers are housed in one unit with three yellow wires going in and constant 14 volts dc from the two red and black wires leaving the small very efficient waterproof unit at up to 40 amps, simple.