GS wiring question

[Hap Call]

What I am trying to say is that there is no extra energy to burn up...When the R/R senses that the voltage level at the battery is at a suitable level it opens a transistor "switch". This stops any current from flowing. To produce power you need two things electrically - Voltage and current. With an open circuit you cannot have current so you will not have power. The stator will have the windings magnetically saturate and reach a flux level equal to the magnets' flux level. At that point no power is produced. This saturation is the same as inrush current on a motor or a transformer.

Does that make sense?
Hap

It makes sense to me,

but I have some additional thoughts....

The GS regulator has only six-diode rectifying (no tyristors-rectifying).

Additional, there are three zener-diods connected on the AC-side over a resistor to ground and three tyristors also connected to the AC-side and to ground, the gate of the tyristor is connected between the Zener and the resistor.

So I think, if the Voltage is to high, the Zeners opens the gates on the tyristors, which shortens the power to ground and back to the alternator over three of the diods (negative side).

This design "burns" power in the regulator, but if one of the phases is disconnected as in the earlier models you do not "burn" power for that phase, for the reasons you described in your post.

Do you agree Hap?

I do agree, but there are a couple of things that I would like to clarify. First is the idea of an electrical "node". A node is anything in which the electrical potential is the same everywhere. An example would be a wire that is connected to nothing except a battery with the potential of 12V. If this wire were bare, any place you put a volt meter you would see 12 volts. If you were to hook up twenty wires off this single wire they would all read 12 volts (theoretically). This twenty wire "harness" is a single node. Now put a light bulb on one of the wires and run another wire from the bulb to the negative side of the battery. The bulb lights up. The wire that is running to the other side of the battery is a different node because the voltage drop across the bulb puts it at a different potential. You now have two nodes. You have to have that voltage drop for current to flow.

Second, you have one Zener diode that controls the gating of a NPN transistor and a PNP transistor which in turn control the gating of the three thyristors (also called SCRs, one for each phase of the stator). These thyristors allow each phase to become a "node" with no other voltage drop or current path. With no voltage drop available for the current to "flow" across, the current stops and the stator field saturates. With no current flow the no power is produced.

The three phases out of the stator are an AC potential. Due to something called phase angle (involves imaginary numbers) they actually "cancel out" current flow on the negative return.

Hap
Once again my head hurts!

[TheNose]

I'm getting educated beyond intelligence...........

Terry

[kz]

I do agree, but there are a couple of things that I would like to clarify. First is the idea of an electrical "node". A node is anything in which the electrical potential is the same everywhere. An example would be a wire that is connected to nothing except a battery with the potential of 12V. If this wire were bare, any place you put a volt meter you would see 12 volts. If you were to hook up twenty wires off this single wire they would all read 12 volts (theoretically). This twenty wire "harness" is a single node. Now put a light bulb on one of the wires and run another wire from the bulb to the negative side of the battery. The bulb lights up. The wire that is running to the other side of the battery is a different node because the voltage drop across the bulb puts it at a different potential. You now have two nodes. You have to have that voltage drop for current to flow.

Second, you have one Zener diode that controls the gating of a NPN transistor and a PNP transistor which in turn control the gating of the three thyristors (also called SCRs, one for each phase of the stator). These thyristors allow each phase to become a "node" with no other voltage drop or current path. With no voltage drop available for the current to "flow" across, the current stops and the stator field saturates. With no current flow the no power is produced.

The three phases out of the stator are an AC potential. Due to something called phase angle (involves imaginary numbers) they actually "cancel out" current flow on the negative return.

Hap
Once again my head hurts!

Hap, if your head not hurts too much...

This topic has interested me for many years, but I always thought (but never was 100% sure) that the extra power was "burned" either at the heat sink in the regulator or at a separate mounted Zener-diod with heat sink.

All automotive alternators have to be designed for the maximum power consumption of the bike/car, if the consumption is not max. the alternator voltage has to be regulated somehow, otherwise the voltage would increase and damage the electrics on the vehicle, the normal way to regulate the output voltage of a three phase synchronic alternator is to change the rotor field (exiting). Correct?

On the GS we have permanent magnet rotor so this method is not possible (advantages no brushes and no slip rings).

If I recall what I think I understand, and go back to my former BSA 441 1968, that bike had a big Zenerdiod mounted on a heat sink wired between + and -, the alternator was single phase.

In that case, if the voltage went higher than spec. like 14 V or something, the zenerdiod just made a short circuit to ground and burned the power away in the big heat sink? Correct?

Now to the GS...

I can follow your part with the nodes and phase angle, should be 120 degree between the phases and the switch angle of the SCR:s could be any angle according to how you switch the tyristors? Correct?

I can understand that if you somehow are able to "open" the AC circuit, the voltage will drop and then you don't have to "burn" power away.

But, I can't follow you how the voltage can decrease without any additional current flowing somewhere, as current still is floating through the six diode rectifier and as the rotors magnetic field is the same and the bikes power consumption is going down??

Are the tyristors somehow opening the AC-circuit? Do you have a precise circuit diagram of the regulator?

What are the NPN and PNP transistors you described for? Only amplifying or something else?

I'm sure I missed something here, because the development from 1968 to 1984 must include some improvements.......... :?

[Hap Call]

Karl, you have posted a lot of questions there! I will write something up and post it here but it will be a few days before I can finish it.

Hap

[TheNose]

Aren't SCRs and tryristors the same thing? If I understand Hap correctly, the SCRs are not conducting and therefore there is no current flow in the coils. If they pass through the magnetic field then no current flow is produced.

I also don't think the transistors are used for amplification. They are probalby used to control the switching of the SCRs. Could be a Darlington pair in the circuit too? The voltage gets high enough, it switches the SCRs so that they do not flow, therefore no current flow in coils, so more voltage. :?

My big question is , Math is already too damn complicated as it is, why do mathematicians have to start imagining numbers to make it even more complicated. Never could do math - don't understand a science that is based on mathematical fact using imaginary numbers.

[kz]

Karl, you have posted a lot of questions there! I will write something up and post it here but it will be a few days before I can finish it.

Hap

Thanks Hap, take your time, it's worth waiting for your comments.

[kz]

Aren't SCRs and tryristors the same thing? If I understand Hap correctly, the SCRs are not conducting and therefore there is no current flow in the coils. If they pass through the magnetic field then no current flow is produced.

Don't know if SCR and thyristor is the same thing but I believe that.

If the SCR opens, there is still a connection between the stator and the bikes DC-electrics through the six-diode rectifier. So there must be current floating somewhere.

Se this model what happends with the Voltage if you change the speed and keep the magnetic field constant.

http://www.medialab.chalmers.se/mdt/elkraft/4a_1.html

click "cylindrisk rotor" then put the lever "F?ltstr?m" on max, that equals our GS permanent magnet rotor.

Now you can change the lever "Hastighet" that equals the revs. on our GS.

You can now see that the Voltage is increasing by increasing speed.

Back to our GS.

1. The "old" wiring with one phase cut then the light is off: no extra current floating, but increasing Voltage in the stator.

2. The "new" wiring short to ground with three SCR the voltage is keeped down, but extra current is floating?