Author Topic: Don't understand, where have the volts gone?  (Read 793 times)

Online KeithJ

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Don't understand, where have the volts gone?
« on: 16.10. 2014 17:54 »
I have recently had my E3L dynamo apart to get it re-plated.  It was working fine before I took it apart.  I have reassembled it and checked it as per the instructions for use with my JG Regulator but on my bench.  Using an electric drill, I can only get about 5V output. 

The dynamo rotated the correct way and motors.  I have "flashed" it.

Wiring it as standard, I appear to get about double the voltage.

Is is usual or does it indicates a fault?

Many thanks, Keith
'59 A10RR + Second engine

Offline warmshed

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Re: Don't understand, where have the volts gone?
« Reply #1 on: 16.10. 2014 20:24 »
Depends on the drill speed but seems about right.

Online KeithJ

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Re: Don't understand, where have the volts gone?
« Reply #2 on: 16.10. 2014 21:20 »
Any idea of why the difference depending on how the dynamo is configured?
'59 A10RR + Second engine

Online chaterlea25

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Re: Don't understand, where have the volts gone?
« Reply #3 on: 16.10. 2014 22:08 »
Hi Keith
JG regulators need internal wiring changes to the dynamo, so normal "flashing" wont work
You need to earth the "F" terminal, lift the "D" brush from the armature and flash battery live to the "D" teminal

http://www.davelindsley.co.uk/faq.html   for help

HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Online muskrat

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Re: Don't understand, where have the volts gone?
« Reply #4 on: 16.10. 2014 22:10 »
G'day Keith.
There's quite a few here a lot better at electrickery than I. When testing did you have it hooked up to a fully charged battery? Might explain why it wasn't charging 6v or more. When you tried it the other way (double voltage) it may have been running open circuit.
Now waiting with helmet on  *bash*.
Cheers
Just saw John's post.
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Online KeithJ

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Re: Don't understand, where have the volts gone?
« Reply #5 on: 16.10. 2014 22:15 »
Thanks for the input.  Not connected to a battery as it is off my bike.  Output both times was generated by a mains powered electric drill driving the sprocket end of the shaft.  Only thing changed was the wiring configuration of the field coil and brushes from standard to JG spec.
ATB
'59 A10RR + Second engine

Offline wilko

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Re: Don't understand, where have the volts gone?
« Reply #6 on: 16.10. 2014 22:26 »
I had the same problem once. Tried another drill with a higher speed and tons of volts!

Online KeithJ

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Re: Don't understand, where have the volts gone?
« Reply #7 on: 17.10. 2014 09:20 »
I had the same problem once. Tried another drill with a higher speed and tons of volts!
How does this explains the different Voltage outputs with the same drill but the dynamo wired differently?
'59 A10RR + Second engine

Online KeithJ

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Re: Don't understand, where have the volts gone?
« Reply #8 on: 17.10. 2014 09:54 »
Hi Keith
JG regulators need internal wiring changes to the dynamo, so normal "flashing" wont work
You need to earth the "F" terminal, lift the "D" brush from the armature and flash battery live to the "D" teminal

http://www.davelindsley.co.uk/faq.html   for help

HTH
John
Yes, you are correct in saying the internal wiring is different and I have tried mine both ways.  With the conventional way, linking D&F to earth I get more volts than when set up and tested for a JG unit. 
In the Instructions I have for the JG unit, it shows how to test a dynamo without the JG unit and no battery.  It does not mention lifting the D brush, just F to earth and D to -ve side of Voltmeter with the +ve side of the Voltmeter to earth and the internal wiring changed accordingly.

I think I have missed something but can't see what.

Could not find any details about testing on the Dave Lindsley site.  Used the information I had supplied with the unit years ago.

ATB
'59 A10RR + Second engine

Online chaterlea25

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Re: Don't understand, where have the volts gone?
« Reply #9 on: 17.10. 2014 21:22 »
Hi Keith,
When wire conventionally joining D & F will simulate full output from the dynamo, it will in effect saturate the field windings
You should have felt more drag on the electric drill this way

If you earth the "F" terminal when wired for JG reg you should achieve the same effect & volts

I always use a 12v headlamp bulb when checking for output, this shows the power output rather than just volts !!  its easy to fool a digital meter  *conf*

HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Offline kiwipom

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Re: Don't understand, where have the volts gone?
« Reply #10 on: 17.10. 2014 21:49 »
hi guys, (It was working fine before I took it apart.) done that a few times. What's that saying: if it aint broken don't fix it, lol,cheers
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Online KeithJ

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Re: Don't understand, where have the volts gone?
« Reply #11 on: 17.10. 2014 22:49 »
hi guys, (It was working fine before I took it apart.) done that a few times. What's that saying: if it aint broken don't fix it, lol,cheers
Yes, good point.  However, the bike has been looking tatty since my last rebuild some 25 or so years ago.  Just kept going on and on but in the end I decided some tlc was needed.
ATB
'59 A10RR + Second engine