Misc: Charging Systems Series ‘C’ Rapide Battery Not Charging

[oexing]

Mike, the two windings on the coil got two functions: The finer winding cares for the voltage control, acting on the voltage side and also for the cut-in contact. The fat winding cares for any over-current or short in the system and from over current it will pull the field wire contact to earth so no more power will be produced in the field coils.
Traditionally the resistor is one winding in one field coil which got 4 wires for identifying it. The resistor will have like 4 ohm, the field 1-2 ohm.
Electronic regulators don´t use the resistor for a medium setting like the original - quite nice I say - but simply short the field to earth in very high switching frequency.
Below a diagram of a Bosch Z-type regulator and a picture of the very old F-Type, with only one moving lever, caring for cut-in and some linkage for the voltage control. Basically the wiring around the dynamo is same like with the later Z-type I still run in the 6 V system Horex in photo. The later type had levers and contacts at both ends for cutout and voltage control - extremely reliable. There are 4 field coils on the Horex, one with resistor winding inside as described.
Besides, there is a photo transistor ignition plus flyweights a/r device there as well. The blackbox at 10 o´clock position is the ignition , the standard coil is under the tank. So all the rest is inside the chrome cover.

Vic

Bosch Z type,

Z-type at 2 o´clock :

 

[Chris. S]

Hi Mike. I used the original Miller voltage regulator, for several years, on a Comet; but I got fed up with having to partially dismantle it every 1000 miles or so, to clean the contacts, due to burning. A small mountain of transferred silver would build up on the lower contact, ref your drawing Fig 55. The result is shorted contacts, and no charge. This problem could probably have been fixed by connecting a modern diode across the contacts; but I fitted an electronic regulator instead, which is still going strong 18000 miles later. The picture is of my original Miller regulator.

 

[Mikethebike]

Mike, the two windings on the coil got two functions: The finer winding cares for the voltage control, acting on the voltage side and also for the cut-in contact. The fat winding cares for any over-current or short in the system and from over current it will pull the field wire contact to earth so no more power will be produced in the field coils.
Traditionally the resistor is one winding in one field coil which got 4 wires for identifying it. The resistor will have like 4 ohm, the field 1-2 ohm.
Electronic regulators don´t use the resistor for a medium setting like the original - quite nice I say - but simply short the field to earth in very high switching frequency.
Below a diagram of a Bosch Z-type regulator and a picture of the very old F-Type, with only one moving lever, caring for cut-in and some linkage for the voltage control. Basically the wiring around the dynamo is same like with the later Z-type I still run in the 6 V system Horex in photo. The later type had levers and contacts at both ends for cutout and voltage control - extremely reliable. There are 4 field coils on the Horex, one with resistor winding inside as described.
Besides, there is a photo transistor ignition plus flyweights a/r device there as well. The blackbox at 10 o´clock position is the ignition , the standard coil is under the tank. So all the rest is inside the chrome cover.

Vic

View attachment 60360


Bosch Z type,

View attachment 60361

Z-type at 2 o´clock :

View attachment 60362

Many thanks, Vic. I think I now understand what's going on with the old set-up. Your Z-type seems to be cleverer, in combining the cut-out and regulation in one unit. Presumably the 4 coils in the Horex are another way of governing the field current but there must be a subtle reason for winding a resistor onto the field pole.
I think I'll stick with the simplified connections plus electronic regulator!
Mike

 

[Mikethebike]

Hi Mike. I used the original Miller voltage regulator, for several years, on a Comet; but I got fed up with having to partially dismantle it every 1000 miles or so, to clean the contacts, due to burning. A small mountain of transferred silver would build up on the lower contact, ref your drawing Fig 55. The result is shorted contacts, and no charge. This problem could probably have been fixed by connecting a modern diode across the contacts; but I fitted an electronic regulator instead, which is still going strong 18000 miles later. The picture is of my original Miller regulator.View attachment 60365

Thanks Chris. I've heard that those regulators weren't as reliable as the literature claimed (tungsten points might have helped). Interesting to see that it's rubber-mounted - that tells me something!
I've no idea what's inside the modern electronic regulators, but I image it's a bit more subtle than intermittently dumping surplus current to earth. I had enough problems years ago with the Lucas regulator.
Mike

 

[LoneStar]

All dynamo regulators operate by limiting current to the field coil, which in turn limits dynamo output from the rotating armature. This is actually a more elegant method than just dumping excess output to earth, which is commonly used with alternators (e.g. zener diodes with big heat sinks).

The original Miller and Lucas dynamo regulators have points which open and close the circuit to the field coil, at a high rate, to achieve the desired average current. Electronic ones use more sophisticated means to the same end.

 

[oexing]

Sorry folks, my writing above about the workings of a traditional regulator was nonsense in so far that the field current is initially connected to ground , starting at the positive brush , through the field coils and to ground when still below battery voltage . Once voltage climbs the regulator voltage contact finger lifts to middle position between both sides at left in diagram. So the field current has to pass the resistor for reaching the ground finally. So in this state the field current will be reduced for less power and voltage.
No excess power will be dumped in Zener-diodes or some such. Those are to be found on permanent magnet alternators as they had no other means to limit voltage before better electronics were available later.
When speeds exceed 7V resp. 14V the voltage contact moves to right side and no more ground connection is available. So then no more power is produced and a new cycle of generation is started from lower voltage. All this action goes on in short durations with some sparking at contacts but will last many thousand hours . I did a conversion for tungsten contacts for wear on an E-Type dynamo regulator, no three phase alternator there in 1964 - and positive earth at that. Actually I like the non-electronic type as I can have voltage as I like it by some minimal bending of spring supports in there, having a multimeter at hand.
The option for resistor housed in field coil is no witchcraft, no other effects from this, just an easy place to put it. The Earles fork BMWs had a resistor mounted next to the 6 V 90W dynamo, not in field coil, no other differences in functions to the older way. Late 250 BMW singles had the resistor on the base plate of the regulator when placed elsewhere on the bike, rather corrosion effected unlike older types under engine covers. You can certainly fit a high load resistor instead of the four wire combi field coil just as well.

Vic