1937 Aero 600cc wiring diagram

[John Wilkinson]

Hi,
Does anyone have a wiring diagram for a Aero 600cc or advise where I could get one.

Many thanks,

John.

[John Wilkinson]

Also, any info please on how to wire in a modern regulator.

[podge]

Hi John

I believe that the 600 cc Aero uses a BTH PA pankake dynamo similar to that on my 1932 350 cc   A 32 Terrier. This dynamo feeds the battery via a BTH cutout - no regulator. When I rebuilt the electrics on my A 32 the cutout was missing and they are like hen's teeth to find even at autojumbles. So I made an electroniic cutout. My dynamo produced 8.3 volts and would generate a maximum of 2.6 amps. I found a diecast box at Maplin Electronics which is the same size as the BTH cutout, into this I put a 6 amp diode from Maplins in series with the dynamo output and a 10 amp fuse for prudence and to stop boiling the battery I used a 6.8 volt 10 watt zener diode that I bought from Mauser Electronics in USA. You also need to fit an isolating switch in series with the battery since if the bike is left for a month without running, the battery will slowly discharge via the reverse current through the cutout diode. This system works well and has been running for 4 years. The new cutout box fits in the same position as the old BTH cutout, with the zeber diode mounted beneath it on a piece of aluminium angle as a heat sink.

Hope that this info is useful - contact me if you want more data.

Regards

Paul

[John Wilkinson]

Hi Paul,
Thanks for the information regarding the voltage regualtor for my Douglas. I have gathered all the parts together from Clacton Electronics and assembled them and all seems well. Unfortunatley, I find my dynamo which was producing 8.2 volts is now only producing 6.2 volts so further investigation is required.
John.

[podge]

Hi John

The Zener diode will clamp the voltage across the battery to 6.n volts. Please call me on 02376 471921 and we can discuss.

Regards

Paul

[podge]

Hi John

Further thoughts. Zener diodes have a plus/minus percentage tolerance. Although nominally 6.8 volts mine clamps at 6.4 volts. The dynamo produces 8.2 volts without the zener diode in circuit and charged the battery at 2.6 amps with the bike running at 40 mph, this caused the battery boiling. Now with the zener diode clamping I get a charge of 250 milliamps which effectively trickle charges the battery. With the rear lamp and pilot lamp on the battery discharges at 1 amp, but with the engine running the charge rate is plus 250 milliamps. I use a 24 watt headlamp bulb, which with the rear lamp discharges the battery at 4.5 amps, but with the engine running this decreases to a discharge of 1.3 amps. the power difference of 8.2 volts minus the zener clamp of 6.4 volts = 1.8 volts at 2.6 amps = 4.6 watts is dissipated in the dynamo wiring and zener heatsink.

I hope this is clear

Regards

Paul