CB1100 Alternator

[postoak_imp]

Thanks Max, that sheds some light on it but this sentences confuses me:

Quote: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.
Which coil are you referring to (stator, field, rotor, or ignition) and what is the spring you are referring to?

[max]

Thanks Max, that sheds some light on it but this sentences confuses me:

Quote: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.
Which coil are you referring to (stator, field, rotor, or ignition) and what is the spring you are referring to?

Which coil are you referring to (stator, field, rotor, or ignition) and what is the spring you are referring to?
This small coil was inside the regulator and maintained the 14 volts against the( adjustable ) spring tension.
It was the most common regulator system used on all vehicles at the time, it's mechanical/electrical, the more tension on the spring the higher the regulated voltage, the spring is the equivalent to the float height in the cistern.

The spring would pull against the magnetic field, if the magnetic force was getting stronger ( higher voltage ) it would overcome the strength of the spring, open the contact and break the supply to the field coil, voltage would lower, contact would close again etc.
so it would be vibrating in it's own rhythm and maintain 14 volts

[Lord Popgun]

And thankfully those things are over and gone! Here is a pic schematic of one. https://www.google.com/search?q=car+volt...0djqJ4LaM:

And here is one that is like ours: https://www.google.com/search?q=car+volt...0djqJ4LaM:

It uses SCR’s, not MOSFET’s though.

[SportsterDoc]

Great responses from Popgun and Max, with helpful info from pekingduck.

Max, does the CB regulator draw full current at all times and waste unused or only draw what is required?

The latter is a benefit of Cycle Electric regulators over stock H-D regulators. I do not know as much about Honda as Harley.

[pekingduck]

Thanks, why did the field coil type reduce HP loss when the battery didn't need charging? Was power to the field coil cut (using some sort of feedback mechanism)?

Brushes on the CBX lasted between 10 and 15 thousand miles , always had a spare set with me and easy to change on the road.
Early CBX 's were often made redundant because owners were afraid of an expensive repair or new alternator .Brushes were very cheap.

What do you mean they were made redundant?
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?

Yes, as Max said, the mechanical regulator had a set of points that an electromagnet would close when battery voltage dropped enough to weaken the electromagnet. When it was charging, it added some frictional drag from the magnetism. Some production road racers used to have a toggle switch to interrupt the power to the exciter coil. Maybe one or two horsepower more, maybe it was all in their heads.

[max]

Great responses from Popgun and Max, with helpful info from pekingduck.

Max, does the CB regulator draw full current at all times and waste unused or only draw what is required?

The latter is a benefit of Cycle Electric regulators over stock H-D regulators. I do not know as much about Honda as Harley.

Doc, the regulator is small and efficient ( not much heat to dissipate ) it somehow ( thanks popgun ) switches the output devices average current very fast to maintain regulated output.

It works by switching the output devices hard on and off in the same way the old school regulator did but at a much faster rate, so the device does not dissipate a lot of power, it only dissipates the amps times the volt drop across the device, let say 20 amp across 0.02 volts = 0.4 watts multiplied by 3 or six devices is 1.2 watts plus control circuitry and diodes if any.

The trick is how long to switch it on for in relation to the off period, the "width" of the "on" pulse,
This "time on" is the variable that determines how much energy is released in the electrical system to maintain 14 volts, which is done by the electronic regulator drivers inside the device.
This ratio is called the "duty cycle" and is anywhere between 0% and 100% depending of the load at the time

Nothing or very little is wasted and no ballast ( old way of dumping unwanted energy ) is used, it is simply not generated.

The output of an alternator such as ours generates as much as 50 volts ac unloaded, we just nibble enough of it ( regulate ) off to supply the electrics of the bike.

Just used practical values to explain, the actual values will be different but in the ballpark.

[postoak_imp]

I see Max, I missed the sentence where you said you were now talking about the voltage regulator.

Since there is no field coil or rotor coils voltage to control, how do our regulators work? Do they send excessive current to ground?

[pekingduck]

I see Max, I missed the sentence where you said you were now talking about the voltage regulator.

Since there is no field coil or rotor coils voltage to control, how do our regulators work? Do they send excessive current to ground?

Yes.

[SportsterDoc]

Interesting thread

Pre 04 EVO Sportsters have only a single phase stator and output 24 VAC per 1,000 RPMs. Thus, at 6,000 RPMs, the regulator/rectifier is seeing 144 VAC. Unlike Honda, the regulator is mounted in front of the frame for cooling.

http://www.cycleelectricinc.com/Diegnosi...nators.htm

[Houtman_imp]

Thanks, why did the field coil type reduce HP loss when the battery didn't need charging? Was power to the field coil cut (using some sort of feedback mechanism)?

Brushes on the CBX lasted between 10 and 15 thousand miles , always had a spare set with me and easy to change on the road.
Early CBX 's were often made redundant because owners were afraid of an expensive repair or new alternator .Brushes were very cheap.

What do you mean they were made redundant?
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?

What do you mean they were made redundant?
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? With redundant I meant that often the owner did not repair the bike and just let it sit in his garage/shed and after a while tried to sell it.
Once I bought a 79 CBX with only 14000 miles on it for $ 600 in Upstate NY and the only thing it needed was a new set of brushes. The bike would not charge/run and owner afraid of repair bill

After some years later the cheap and easy repair became well known and than the bikes were not that cheap any longer !