Hub Dynamos

[Deleted member 24574]

How do they work?

Do they produce AC?

 

[keithglos]

Re:

A multi pole magnet revolving around windings in a soft iron core.

This is an alternator, and if Sturmey Archer should produce 6 volts up to about .3 amps, or a little more.

Keith

 

[Deleted member 24574]

Re:

Mine is producing zero output. I shal dismantle it and look for a fault

 

[keithglos]

Re:

There is a theory that you should not drop the magnet out without a keeper. I had a keeper, (soft iron ring that fitted inside the magnet) but have taken out the magnet with no problems without one.

Can you feel the magnetic drag as you turn it?
If you dont have a meter try a small torch bulb across the 2 nuts with a bit of wire, you dont need to turn fast if you have a lower voltage bulb.

Keith

 

[Deleted member 24574]

I will take a look at it an report back ...

 

[Deleted member 24574]

Ok ... I have it working although still slightly confused.

Seems a previous owner had tinkered and got the wiring all muddled up ... all sorted now.

The hub is wired to the headlight as is the rear light.

The headlight has a 3 position switch; as far as I can see the switch has two off positions and one one ... why the need for a 3 position?

Also ... anyone got the glass for a 60s dynamo headlight?

 

[keithglos]

Re:

Lamp probably from the 1950s when Raleigh made a battery container with a metal rectifier placed on the seat tube of some models, so that the light could be switched on when stationary. The batteries almost always corroded the steel casing.

Keith

 

[Deleted member 24574]

Ah, are you saying there would be some sort of battery back up for the 3rd position on the switch.

 

[Midlife]

Battery packs were usually attached to the seat tube and looked like a tube from a kitchen roll

Shaun