3 brush model 52 question

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Scrap
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3 brush model 52 question

#1

Post by Scrap »

Battery reads 6.1 volts, motor off. Motor running, revved up, key switch in 1st position, generator light turns off but voltmeter still reads 6.1 volts. Key switch in 2nd position, headlight on, rev it up considerably and voltmeter reads 6.4 volts max. Wiring is correct, continuity on all wires checks out. The points close on the cut-out relay (the gen. light went out) so the generator, I assume,is polarized. This bike had stopped charging when I took it out of service many years ago. Before I recently got it back on the road I took the genny and the cut-out relay to an old fashioned auto generator shop and he said it was working fine charging at 4 amps, and he just cleaned it up. When I showed him the wiring diagram he thought it would not charge at all if the switch terminal on the generator was not getting juice from the key switch as in position 1. He knew all about 3 brush generators but was not aware of the characteristics of this particular system. Should I bring it back to him with the service manual or do I need a specialist? Are there any tests I should do myself. He said if I ran a jumper from the switch terminal to the relay terminal I should see really high voltage but to be careful not to fry anything. I hesitate to do this or can I try it momentarily if there is any point in doing so. Will i risk doing any harm to the battery?
Thanks
Sam
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Re: 3 brush model 52 question

#2

Post by 58flh »

Scrap---Dont assume its polarized--if you disconnected it just give it a quick flash from batt. to A term. on genny ,then start it & see if your voltage at the batt. is reading 7 or better at around 2000RPM. And check your GROUNDS.---Richie 8)
1950Panhead
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Re: 3 brush model 52 question

#3

Post by 1950Panhead »

he said it was working fine charging at 4 amps
Your generator is charging.
If there is another problem tell us, otherwise your ok.
Jerry
Scrap
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Re: 3 brush model 52 question

#4

Post by Scrap »

1950Panhead wrote:
he said it was working fine charging at 4 amps
Your generator is charging.
If there is another problem tell us, otherwise your ok.
Jerry
Why is not charging on switch position 1, ignition on, lights off? And shouldn't I see more than 6.4 volts on position 2, juice from the key switch to the switch terminal on the generator and I turned off the headlight with a toggle switch that is on the headlight shell.
Scrap
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Re: 3 brush model 52 question

#5

Post by Scrap »

58flh wrote:Scrap---Dont assume its polarized--if you disconnected it just give it a quick flash from batt. to A term. on genny ,then start it & see if your voltage at the batt. is reading 7 or better at around 2000RPM. And check your GROUNDS.---Richie 8)
The fact that the generator dash light turned off means the points on the cut out relay were closed, wouldn't that be the same as a flash. I will flash it as you described anyways. Could it be a bum battery? It's a new Chineese 6 volt from the HD Dealer.
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Re: 3 brush model 52 question

#6

Post by Cotten »

Richie!

My Model 52 just says 'switch' and 'relay'.
Which is the "A"?

....Cotten
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Re: 3 brush model 52 question

#7

Post by Panacea »

Armature...
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Re: 3 brush model 52 question

#8

Post by hogboy52 »

The "Relay" is the "A" terminal there is only one regulated field coil. "Switch" goes to the second "booster" field coil which is fed straight battery voltage to compinsate for the extra drain of the headlight. This alone when switched on will polarize the generater.

The third brush regulates the voltage level. Remove cover, loosen the screws and shift untill you have 6.8-7.0 volts reading.
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Re: 3 brush model 52 question

#9

Post by Cotten »

Thanks Hogboy52!

So if Scrap has a second switch to defeat his headlight, the system can go out of balance?

....Cotten
Scrap
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Re: 3 brush model 52 question

#10

Post by Scrap »

with the key switch in position one, If the generator light is on and I don't see anything other than static battery voltage of 6.1 volts, isn't something wrong? It should still produce some charge shouldn't it?
Scrap
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Re: 3 brush model 52 question

#11

Post by Scrap »

hogboy52 wrote:The "Relay" is the "A" terminal there is only one regulated field coil. "Switch" goes to the second "booster" field coil which is fed straight battery voltage to compinsate for the extra drain of the headlight. This alone when switched on will polarize the generater.

The third brush regulates the voltage level. Remove cover, loosen the screws and shift untill you have 6.8-7.0 volts reading.
Adjust with the lights on or off? Does it matter?
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Re: 3 brush model 52 question

#12

Post by awander »

hogboy52 wrote:The "Relay" is the "A" terminal there is only one regulated field coil. "Switch" goes to the second "booster" field coil which is fed straight battery voltage to compinsate for the extra drain of the headlight. This alone when switched on will polarize the generater.

The third brush regulates the voltage level. Remove cover, loosen the screws and shift until you have 6.8-7.0 volts reading.
Just a quibble-on the 3-brush generator with cutout relay system, there are actually "no" regulated field coils(unless you count the one fed from the 3rd brush as regulated-I would call it "adjusted")

The Relay terminal is the output of the Generator, analogous to the "A" terminal on later generators.

The Switch terminal is the extra field coil, switched on when the lights are switched on.


Also, the 3rd brush does NOT regulate the voltage level. It regulates how much current the generator puts out. This will affect the voltage level, depending on the load, the condition of the battery, etc.


A generator that was tested to put out 4 Amps is probably not adjusted correctly for the motorcycle. From memory, the adjustment spec was 3 to 4 amps INTO THE BATTERY, after all of the lights and ignition take their current.

the generator needs to be adjusted while on a running bike.
Scrap
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Re: 3 brush model 52 question

#13

Post by Scrap »

awander wrote:
hogboy52 wrote:The "Relay" is the "A" terminal there is only one regulated field coil. "Switch" goes to the second "booster" field coil which is fed straight battery voltage to compinsate for the extra drain of the headlight. This alone when switched on will polarize the generater.

The third brush regulates the voltage level. Remove cover, loosen the screws and shift until you have 6.8-7.0 volts reading.
Just a quibble-on the 3-brush generator with cutout relay system, there are actually "no" regulated field coils(unless you count the one fed from the 3rd brush as regulated-I would call it "adjusted")

The Relay terminal is the output of the Generator, analogous to the "A" terminal on later generators.

The Switch terminal is the extra field coil, switched on when the lights are switched on.


Also, the 3rd brush does NOT regulate the voltage level. It regulates how much current the generator puts out. This will affect the voltage level, depending on the load, the condition of the battery, etc.


A generator that was tested to put out 4 Amps is probably not adjusted correctly for the motorcycle. From memory, the adjustment spec was 3 to 4 amps INTO THE BATTERY, after all of the lights and ignition take their current.

the generator needs to be adjusted while on a running bike.
Should I assume that I should adjust the 3rd brush with the lights on? What about the generator light staying on with the switch in position one? Is this also a function of the position of the third brush? Does it affect the first field coil as well as the extra coil?
awander
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Re: 3 brush model 52 question

#14

Post by awander »

I am guessing by "Position 1" you mean ignition ON, Lights OFF.

The way the generator works is as follows:

With the lights off, only one field coil in the generator is on; it is connected between the Positive brush, and the 3rd brush. The 3rd brush is adjustable in a range between GND(Negative) and Positive. The closer the 3rd brush is to the Positive brush, the less current will flow in the field coil, and the less output you will get from the generator.

The second field coil has one end connected to the Negative brush. The other end of this coil is connected to the Switch terminal on the Generator. It is not connected when the lights are off. When you switch the lights ON, the switch sends full battery(or generator) voltage to the Switch Terminal, energizing this coil and causing the generator to put out more current.

You should be able to adjust with the lights either ON or OFF, and the second coil is supposed to compensate for the current draw of the lights, keeping the charging current(into the battery) roughly constant.
Scrap
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Re: 3 brush model 52 question

#15

Post by Scrap »

awander wrote:I am guessing by "Position 1" you mean ignition ON, Lights OFF.

The way the generator works is as follows:

With the lights off, only one field coil in the generator is on; it is connected between the Positive brush, and the 3rd brush. The 3rd brush is adjustable in a range between GND(Negative) and Positive. The closer the 3rd brush is to the Positive brush, the less current will flow in the field coil, and the less output you will get from the generator.

The second field coil has one end connected to the Negative brush. The other end of this coil is connected to the Switch terminal on the Generator. It is not connected when the lights are off. When you switch the lights ON, the switch sends full battery(or generator) voltage to the Switch Terminal, energizing this coil and causing the generator to put out more current.

You should be able to adjust with the lights either ON or OFF, and the second coil is supposed to compensate for the current draw of the lights, keeping the charging current(into the battery) roughly constant.
Thanks for the explanation. I'll adjust the third brush accordingly.
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