Six volt

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Originally submitted by T.

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12 Volt Generator on a Grey Motor. The layout is similar to a 6 volt Grey Motor. Click to Enlargen. Photo by Sherro.

Six Volt Systems:


In so many ways the words "6 volt system" is just a term.
There is no reason why a 6 volt system of a given year of manufacture can't equal a 12 volt system of a given year in performance.
The special difference a 6 volt system presents is that every cable has to carry twice the current as a 12 volt system in order to deliver the same power.

Cable Sizes:

Because the current through each conductor is double there is potential for each cable to
suffer double the voltage drop if the cables aren't appropriately rated or replaced if they have oxidised through exposure to excessive heat or been overloaded.

System Voltage:

Any automotive electrical system has a system voltage which is higher than the rated battery voltage. With the engine running and turning fast enough the system voltage of a 6 volt system will be about 7 volts.
This 7 volts provides sufficient energy to recharge the battery and ensure the electrical loads of the car will be carried by the generator.
A vehicle that shows less than 7 volts at the battery with the engine turning above about 1500 rpm will suffer reduced battery life and slow cranking problems.

Dim Lights, Slow Wipers:

Naturally the same cables mentioned in "Dim Headlights, Slow Wipers" need to be replaced if they have become oxidised or are under-rated.
If the charging voltage is not 7 volts, achieving a 7 volt output from the generator will probably require an adjustment of the regulator.

Six to 12 Volt Conversion:

Info posted by Q-ball Nov 18 2006:

48-215 (FX) with 12V Alternator. Click to enlargen. Image by Q-ball.

"...Altered an old Red motor Alt. bracket to bolt to the Genny. mounting points...would you belive the shafts are the same size between the Alt. & Gen.!! just used the old "B" section pulley with a washer behind it..DONE!!
Next change all globes (dash,tail etc) to 12v, fitted a head light relay & wacked in a couple of QH insert far have only bought the relay..the rest has been in the shed!
The headlight conversion was made a little easier by using the headlight harness's from an FJ that had been converted to (6v)sealed beams...these had the right plugs.
Next..fuel is likely that the gauge & sender would have handled 12 volts..BUT..a mate at the local hobby store built me a small regulator..12 volts in, 6 out..the size of a .50 cent coin, over a cup of coffee for $10.
Could have changed the starter, but left it...winds over REAL well.

7806 IC:

A 7806 Regulator Integrated Circuit will convert 12 volts to 6 volts. It has 3 pins.    

    7806 Connections 
  Pin Name  
Pin Function   Voltage  
Pin 1 Input 12 volts
Pin 2 Ground 0v Earth
Pin 3 Output 6 volts

  These can be bought from Jaycar.

6 Volt Battery showing Corrosion on the Battery Terminals and the Coupling Bars. The firewall is suffering too. Hydrogen ions at work again. Covering the Terminal Posts and Coupling Bars with grease would stop the Corrosion. Click to Enlargen. Photo by greizy.
6 Volt Battery showing Corrosion on the Battery Terminals and the Coupling Bars. Poor contact can make cause continual charging and the gases produced can exacerbate the firewall corrosion. Click to Enlargen. Photo by greizy.


7806 Regulator Information



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