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I just sold my KZ650, but earlier this spring I bought a brand new Regulator/Rectifier for it - http://www.z1enterprises.com/detail.aspx?ID=440. I never got around to installing it, and now I'm wondering if I can use it on my '72 CB350 or should I just try and sell it? Being the electrical idiot that I am, I know less than nothing about electrics and don't have a clue if its possible. I plan on taking a bit more time on this bike to learn more of the basics of it.

From my understanding the 350 has a separate rectifier and regulator, so this smaller contained unit would be much neater and easier to hide. Does the type of alternator have any affect on the type of regulator/rectifier you can use? Will it be hard to rewire everything to make this work?

I won't be wiring this up for quite some time but just basically need to know if this unit is usable, or I should stick to the stock setup?
 

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Well, I don't know about the KZ650, but that link says it also fits the KZ400, and those I DO know about.

The KZ uses an electromagnet rotor to generate electricity in the stator windings. The CB uses a permanent magnet rotor.

The KZ regulator varies the amount of current sent to the rotor to vary the amount of electricity produced. Low battery = more current sent = more electricity generated = charged up battery.

The CB regulator simply watches for elevated battery voltage and shunts the alternator output to ground if the battery voltage gets too high.

The KZ alternator is a 3-phase system, so the rectifier has 3 separate systems to rectify each phase.

The CB alternator is a 1-phase system, so the rectifier has only the one phase to rectify.

So, long story short - the KZ set-up won't work on your CB. :(

Kirk
 

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Discussion Starter · #3 ·
Wow, great explanation Kirk, I even understand some of it :) Really appreciate the response. Guess I'll have to try selling it somewhere. I'll probably have more questions when it comes time to wire up the 350.
 

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No worries.

Oddly enough, the Honda SOHC fours of the 70's use the same system as the KZ (electromagnet rotor and 3-phase windings), so perhaps you'd be able to sell it to a SOHC4 enthusiast.

Kirk
 

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Sensei
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What Kirk said, except the 350 is a TWO phase system......Regardless, it would be a waste of time to try to use it on the 350...........
 

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66Sprint said:
What Kirk said, except the 350 is a TWO phase system......Regardless, it would be a waste of time to try to use it on the 350...........

Well, all the singles & twins that have/had the capability to turn off the headlights DO have that extra coil for charging when the lights are on. But, since both coils feed thru the same single bridge rectifier when they're tied together (pink on one and yellow or yellow+white on the other), and since the two coils are joined together at a common point (pink) (rather than two totally separate windings and two separate bridges), I considered it a single phase system.

:mrgreen:
 

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Sensei
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It is two-phase because the instantaneous polarity of the output wires reverses.... In one "phase" the yellow has a positive charge, and as the magnet N pole passes the next coil (which by the way is wound in the opposite direction) the yellow wire becomes the negative.....
Only two diodes are required to rectify each output "leg"...One to allow positive flow and prevent negative flow, and the other oriented to allow negative flow and prevent positive.....The three phase systems use 6 diodes (three pairs) and the 350 uses 4 diodes (two pairs, so two phase)
A single phase system would have one output wire (leg) permanently grounded, and would only charge through to the battery when a specificly oriented (correctly directional) pulse was flowing through it. (No regulator required)...When the opposite pulse "hits" it is immediately grounded and does not contribute to the charging......The other leg runs to one or two diodes that similarly "allow" a correctly oriented power pulse to reach the battery positive, but either shunt the opposite pulses to ground, or in the single diode version simply "waste" the incorrectly oriented pulse ( this is similar to the system used by Lucas on the Triumphs, and is not only very inefficient, it generates LOTS of heat......Note that on the Triumph, it is closer to a true single phase because ALL the coils are wound in the same direction)
 

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Ah, I see where you're coming from, but the switching polarity is not what defines a phase.

In power generation, a phase is a separate winding regardless of whether one end is grounded or not. In three-phase power generation, there are three separate phases.

In the Honda alternators we're talking about, there are two coils, but both connect to the same two points on the rectifier bridge. The coils are in parallel with each other, but in phase, that is, not out of step. There are 6 wound poles in the stator, but also 3 (+) and 3 (-) magnets on the rotor. The orientation of the magnets combined with the coil winding direction (clockwise or counter-clockwise) ensures that the current from both coils is always flowing in the same direction as each other. So, at any given moment, the current flow in BOTH coils is always in the same direction. All the output is in phase with each other. It is true that the polarity reverses, but that isn't what defines how many phases a system has. In AC power generation, the polarity reverses. Of course, that's why it's called AC - polarity alternates. But you can have AC 3 phase or AC single phase.

In the Hondas, they have full-wave rectifiers across the one phase. In the Triumph, or any others where one end of the coil is grounded, they are still defined as one phase, but only half-wave rectification. That's what you're describing - full or half rectification, not single or two phases.

Here's a schematic of how they're wound: The second diagram is the important one.





When the yellow wire goes positive (or yellow + white, if the lights are on), current flows thru the upper left diode out to the battery (+). But at the time, the pink is negative BECAUSE IT'S THE OTHER END OF THE SAME WINDING, so current flows from ground thru the lower right diode to the pink. That's the full circuit.

When yellow goes negative, current flows from ground thru the lower left diode to the yellow. Pink is going positive, so current flows from pink thru the upper right diode out to the battery (+). In this way, there is ALWAYS current flowing out to the battery (+). Full-wave rectification.

In the Triumphs, etc. they only have one coil, and one end is grounded. So, current flows out to the battery ONLY half the time. The other half, no current flows. Half-wave rectification.

For single phase, full-wave rectification, 4 diodes are required, as the Honda rectifiers have. At any given moment, 2 will be conducting - one from the winding to the battery (+) and one from ground to the winding. For single phase, half-wave rectification, only one diode is required, and one end of the coil must be grounded.

For 3-phase, full-wave rectification, only 6 diodes are required, but at any given moment, for any given phase, 3 will be conducting rather than 2 - one from the winding to the battery (+) and the other 2 from ground to the winding.
 

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Sensei
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One phase would show as a single sinewave on an ocilloscope.....Correct?
Two sinewaves showing a 120 degree initiating difference (zero point) would be 2 phase...Correct?
 

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Two sine waves showing ANY difference would be two phase, as far as I know. And that may be how the Hondas could be considered a two-phase system - perhaps the white-wire coil and the yellow-wire coil (as I've called them in my own mind) are NOT perfectly in phase as I've described. If not, then it's very odd that the rectifier still uses only 4 diodes in the rectifier, instead of a more complex set-up as in the conventional 3-phase rectifiers. Because, if they're out of phase, then at some point, the currents would cancel each other out (since they DO connect to the same points on the rectifier) leading to less overall power production from the alternator.

The 120 degree "phase lag" is standard for 3-phase utility power generation. One rotation of the magnet is 360 degrees, so three separate phases, equally spaced around the circle gives a 120 degree difference between the three phases.


Deacon, just go back to my first post - the basic summary. :mrgreen: :mrgreen:
 
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