Lucas electrics - Richard Hall
I just spent half a weekend struggling to persuade a Lucas dynamo charging system to do what it was designed to do. While looking for information on the control box, I came across this, which should amuse anyone who has ever owned an old Landie or British Leyland car:

www.landroverclub.net/Club/HTML/Humor_electrics.htm

By the way, can anyone explain to me, very simply, what the three coils in a Lucas control box actually do?

Richard Hall
bangernomics.tripod.com
Lucas electrics - terryb
Well, the middle one is to keep the other two apart......
Lucas electrics - Peter D
The first one determines when the dynamo voltage is greater than the battery voltage and clicks in as you should obverse. This extinguishes the red light and the contacts remain closed until the engine is turned off. Failure or miss adjustment of this will cause the light to stay on and current to be drawn by the dynamo until the battery is almost flat.

The second coil controls the field coil in the dynamo thus controlling the output current of the dynamo. The third controls the maximum voltage that will be applied across the battery 14.2 max.

The previous version only had two coils, Charge or not and current. These were ok but were prone to over charging a battery by too higher terminal voltage and boiling them dry.

From memory the 3 stage units also required a direct dedicated wire connection from the unit to the battery to sense the voltage at the battery.

Regards


Peter