Author Topic: Dynamo checking  (Read 585 times)

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Online MilitaryRon

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Dynamo checking
« on: December 26, 2018, 10:31:19 am »
Graham, Owen or anyone else who wants to chip in or learn.

I've just replaced a none working dynamo on the WD Triumph I'm currently restoring and am now looking at the none working dynamo. I've taken the new brushes from it and fitted them in the one that is now on the bike. I wonder if you would confirm my findings of the checks I'm doing please.

Touching the probes of my multimeter together gives me a reading of .4 ohms. to start with. Checking the resistance of the field coil is 3.3 ohms minus my .3 = 3 ohms. Checking the resistance between all the adjacent segments on the armature commutator is .6 each minus my .3 = .3 ohms.......Does this all sound OK? Maybe something was miss wired by whoever fitted the new brushes? 

Ron

Offline mark555550

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Re: Dynamo checking
« Reply #1 on: December 26, 2018, 11:12:55 am »
Hi Ron,

If I am reading the figures correctly your readings seem to be ok according to the attached link, obviously readings will differ between manufacturer.

Hope this helps regards Mark.

https://dunhackin.com/index.php/topics/25-the-dynamo-and-lighting-set
1956 BSA C12
1965 BSA C15
1994 Kawasaki VN750

Offline Owen

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Re: Dynamo checking
« Reply #2 on: December 26, 2018, 11:40:52 am »
Sounds good to me.
I'm sure you have done this already but, have: -
Tried motoring the dynamo motor when connected to a battery?
Are the coil/brush wires fitted the correct way round for the rotation?
Flashed the dynamo? (I one flashed it, twice by mistake and wondered why it did not work).
Do you get any output from the dynamo?
Was there anything wrong with the original dynamo?
Have you checked the wiring for any bad connections?

« Last Edit: December 26, 2018, 12:13:45 pm by Owen »
1940 C12 (350cc)
1945 C10 & C11
1953 C10 & C11
Anyone want a B20 in need of a lot of tlc

Offline Vreagh

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Re: Dynamo checking
« Reply #3 on: December 26, 2018, 11:55:24 am »
You also need to check resistance between commutator and core (shaft), also, field and body. There should be open circuit.

Online MilitaryRon

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Re: Dynamo checking
« Reply #4 on: December 26, 2018, 06:35:23 pm »
Thanks for the replies chaps, but at this time I need to get back to queries with the working dynamo on the bike. The dynamo motored like a gooden on the bench....in the right direction. It lit up a 6V bulb on tick over and actually blew the bulb when I revved up. So tried again with a 12V bulb and it lights up a treat.  When I put my multi meter probes on my brand new Cyclon dry cell battery, I get 5.9V Which does not increase when revved up. This was on the Wassels solid state regulator that was already fitted. So I changed that for an original mechanical MCR1 regulator (Working condition unknown) and got the same result. So I then installed a brand new AO solid state regulator that I'd bought some time ago, and again no increase in volts at the battery. I've checked the continuity of all leads and treble checked that they are installed correctly. What on Earth am I missing??

Vreagh I will catch up later about your comments regarding "open circuit" My priority at the moment is not to be beaten by my main charging problem. I spent 5 hours on it this morning but had to vacate the workshop in order to attend a family Christmas function.......Bah Humbug!   Ron

Offline Owen

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Re: Dynamo checking
« Reply #5 on: December 26, 2018, 07:28:55 pm »
What is the voltage at: -
Ignition off but battery connected?
Ignition on but no engine running?
Engine running no lights on above tickover?
Engine running with lights on above tickover?
Can you try with a known good battery and regulator?
1940 C12 (350cc)
1945 C10 & C11
1953 C10 & C11
Anyone want a B20 in need of a lot of tlc

Online MilitaryRon

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Re: Dynamo checking
« Reply #6 on: December 26, 2018, 07:42:25 pm »
There is no ignition Owen. It's magneto.  As I said, I've tried 3 regulators one is brand new. Battery is also brand new and started at 6.3V but now at 5.9V
Dynamo flashed Neg earth.

Offline Owen

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Re: Dynamo checking
« Reply #7 on: December 26, 2018, 08:00:34 pm »
Do you have an ammeter on the bike,  if so is it moving at all?
I would flash it again.
1940 C12 (350cc)
1945 C10 & C11
1953 C10 & C11
Anyone want a B20 in need of a lot of tlc

Offline chaterlea25

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Re: Dynamo checking
« Reply #8 on: December 26, 2018, 08:22:13 pm »
Hi Ron,and All,
Is there enough juice in the battery to light the headlamp?
If not charge the battery, I know the AO reg will not work with a low battery
A quick and dirty trick to kick the dynamo into action is (with the engine running)
Disconnect the F wire from the dynamo
Take a wire from the battery live side and  stuff the other end in the F connection on the dynamo
This excites the field and puts the dynamo into full output you should then see a pos charge on the ammeter and the battery voltage rise
You can check voltage reading on the D terminal, the battery should be almost the same if all the wiring is good
If there's still no charge then the cutout part of the regulator is not working (or wiring problem)

I have found a few dynamo's that needed running like above for a while to sort them out

John

Online MilitaryRon

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Re: Dynamo checking
« Reply #9 on: December 26, 2018, 09:00:47 pm »
Owen John, thanks for the tips so far. Yes the headlamp is bright but I'm quite sure that the CZ27  ammeter is not working, but I'll live with that as long as I know the system is charging OK. John I trust what you say and will give it a go. How long is it safe to leave it running like that? So to check charging, are you saying put multimeter pos probe on D terminal and neg probe to earth, instead of across battery terminals.  I'll also re-flash it before I start. I'll try and get a buddy to help me as it's awkward on your own holding probes and altering revs..........Are you around over the next few days Graham?

Were taking a ride out to Swanage (I think) at 9 am tomorrow (Thurs) if anyone fancy's it. Meeting at Branksome station car park at 9.  Ron
« Last Edit: December 26, 2018, 09:09:50 pm by MilitaryRon »

Offline chaterlea25

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Re: Dynamo checking
« Reply #10 on: December 27, 2018, 12:23:26 am »
Hi Ron,
You could leave the field connected for quite a while, the field is connected while the dynamo is charging anyway
once the set voltage is achieved the regulator switches off the field, when the voltage decreases the regulator switches on again,
With a load on the battery this happens rapidly as the bike is ridden along, mechanical regulators have a resistance across the regulating contacts to stop the points arcing

Quote
are you saying put multimeter pos probe on D terminal and neg probe to earth,

Yes, this will tell if the dynamo is producing voltage, then you can follow the wiring diagram along the different connections if the voltage is not getting to the battery

John

Online MilitaryRon

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Re: Dynamo checking
« Reply #11 on: December 27, 2018, 06:16:23 am »
Thanks John. I'll be on the case after our ride out.  Ron

Offline Ginge

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Re: Dynamo checking
« Reply #12 on: December 27, 2018, 06:28:22 am »
Three regulators not producing Ron....might be a bad earth to regulator.

If the Dynamo is producing enough to blow bulbs then it seems to be producing something.
Ginge.

Offline timsdad

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Re: Dynamo checking
« Reply #13 on: December 27, 2018, 07:46:40 am »
My money is on the regulator(s) if all connections are good - and you know they are, Ron. If the dynamo is pushing it out, and the battery is not getting it, then the regulator must be stopping it getting through.

The first one is faulty, and I don't really trust Wassel electrical stuff, the second one has been laying around and needs tinkering with, and the third is a crap AO one that, as John advised, may need anything from five and a half to over six volts to kick it into life.

Been there, done that and I wouldn't touch an AO 6 volt regulator with a barge pole. I've struggled home with no lights many times on my B31 and stranded on the side of the road with my coil-ignition Real C12 when I just kept giving Mr Osborn the benefit of the doubt.


Ray
Just a motorcyclist.

Online MilitaryRon

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Re: Dynamo checking
« Reply #14 on: December 27, 2018, 07:57:09 am »
It's driving me mad Ginge! I've checked the continuity of all the wiring, everything is as it should be......I think. I've been restoring these old bikes for over 30 years and working on them before that.......I'll get there I'm sure.

I agree about the Al Osborne regulators Ray, but I've had this one on the shelf for years and assumed that I couldn't possibly have 3 duff regulators in a row. As you know, mag ignition is not reliant on a battery, so it's not critical. The new battery is at 5.9V so that shouldn't hamper the AO reg.  I'll play around with John's suggestions before I order another DVR2 reg.  Ron