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Messages - Tom Walker

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American Bikes / Re: any Electrical Gurus out there?
« on: January 21, 2016, 12:01:59 PM »
Thanks, that has given me something to chew on!
I will do some tests and check the earthing of the alternator and the magic box.

American Bikes / Re: any Electrical Gurus out there?
« on: January 20, 2016, 03:40:06 PM »
Its a 3 wire unit, made for Harley alternator models, so can only be for 12 volts. It must be charging, because the headlight is much brighter when its running.

American Bikes / Re: any Electrical Gurus out there?
« on: January 20, 2016, 10:59:32 AM »
Sorry if this is long winded. After trawling around for an hour, this chap seems to know what he's talking about. It may help if you are kind enough to bother reading it...

"The alternator on cars have a three phase stator. Harley's have a single phase stator. The Harley's regulator puts out a pulsed DC voltage. Without a battery the ignition system can't work. The stator on a harley puts out a AC voltage when the magnets on its rotar spins around it. Several times per revolution its output either +, - or zero.
The regulator on a Harley first limits the peak AC voltage by shorting out anything it doesn't need to maintain the output voltage. This is why it has cooling fins and gets hot. It then uses a bridge rectifier in the reg to convert the regulated AC into DC.

There are several ways a harley charging system can take a shit.

1. The stator shorts out. Disconnect the two wires coming out of the primary and using an ohm meter see the is continuity to ground.
2. The stator is open. Check for continuity between the two wires.
3. The magnets come unglued from the rotor. Check stator voltage while the bike is running it will read low, also the engine will have a strange vibration.
4. The regulator has a shorted SCR. you can spot this one from the smoke it produces while the engine is running.
5. The regulator has a shorted output diode. This one will make the regulator melt and burn the wire going to the battery. It keeps on smoking until the bat is dead or the wire burns into.
6.  The regulator has a SCR that failed in the open mode. Lights burn out and the battery overcharges.
7. The regulator has a diode that fails in the open mode. The battery goes dead after awhile."


American Bikes / Re: any Electrical Gurus out there?
« on: January 20, 2016, 10:27:03 AM »
Thank you both for your suggestions. I am not an electrics man. As you say, mark2, I dont understand why the regulators I have used (they are what I call "solid state", ie little black boxes with cooling fins, not tins with points and coils in!), dont apply charge, then sense a full battery and stop charging. Its obviously not as simple as that, for some reason, they dont "recognise" the fully charged state of the small battery.

Chater, if you have a possible solution with a" blocking diode on one phase of the alternator", please could you give me more information as to how I do that in practice? Im not afraid to have a go. Please check back, I will go and find some specs on the alternator.

Meanwhile, in basic terms, the alternator is one of those which has magnets in a "flywheel" rotating around several small static coils. The alternator output is 2 wires.The regulator has those 2 going in, and one coming out to the battery. The unit has to be earthed.

Thank you for your help.   

American Bikes / Re: any Electrical Gurus out there?
« on: January 19, 2016, 10:20:07 AM »
Thank for that. I have tried 2 different regulators and the result is the same. I suppose the fact is that the alternator has to do some work, so the energy has to go somewhere. I was hoping there could be a clever electrical gizmo which would switch off the alternator when its not needed. Probably asking the impossible!

American Bikes / Re: any Electrical Gurus out there?
« on: January 18, 2016, 11:25:46 PM »
Start with charged baattery. No great draw cos I kick it. (ie one accel coil) Running for 5 mins still showing 13.5 volts.

American Bikes / Re: any Electrical Gurus out there?
« on: January 18, 2016, 02:39:45 PM »
Thanks Mark. I can see the sense in doing that to check if regulator is working. If it is, is there any way of reducing the alternator output? Maybe fit some kind of resistance?

American Bikes / any Electrical Gurus out there?
« on: January 18, 2016, 11:53:06 AM »
I have built a Harley special, without room for a normal Harley sized battery. I have to use a small gel type. The charging system works, just too well! The headlight is too bright and blows bulb after a while. The battery overcharges and gets hot. I am using a Zodiak solid state regulator. The engine is a 1970 something Shovelhead.

Can anybody suggest a way forward? thanks, Tom.

Identify these bikes! / Re: Albion gearbox
« on: September 09, 2010, 12:48:04 AM »
Come on lads, someone must have an idea ! Is the kick start blanked off because its a racing box ?

Identify these bikes! / Re: Albion gearbox
« on: September 07, 2010, 04:52:57 PM »
Hi Jari/Members, I'll attempt to post a picture. Thanks in advance for any help.

Regards, Tom.

Identify these bikes! / Albion gearbox
« on: August 06, 2010, 12:54:13 PM »
I wonder if anyone can tell me about a gearbox I bought at Stanford jumble. It is a 4 speed Albion box with RCZ 653 stamped on the case. It is medium weight, I would say, with a gear indicator, and mounts on single bottom swivel, and single top through bolt.

Thanks in advance for any help on what bike it is off.


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