testing generator output advice please
- Thread starter Kube
- Start date
rotorwrench
Well-known member
Amperage can be checked in the line between the battery and the generator output terminal on the cut out if a full circuit is set up. The output would connect to the discharge side of an ammeter and the charge side of the ammeter to the negative post on the battery. This is for positive ground systems.
Voltage can be checked at any point in the circuit and at any convenient ground portion of the circuit. Voltage increases with the output amperage per Ohms law. The higher the output amperage, the higher the voltage.
PS: I have a tendency to post and then go back and proof read. It's probably not a good habit but I try. My wife had a honeydo for me so I was late.
Voltage can be checked at any point in the circuit and at any convenient ground portion of the circuit. Voltage increases with the output amperage per Ohms law. The higher the output amperage, the higher the voltage.
PS: I have a tendency to post and then go back and proof read. It's probably not a good habit but I try. My wife had a honeydo for me so I was late.
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katy
Well-known member
Typo?
nkaminar
Well-known member
The battery should be fully charged after a start in about 15 minutes of normal cruising speed. Either go for a ride or set the engine at a fast enough idle that the ammeter shows charging. After 15 minutes measure the battery voltage. If it is a 6 volt car the battery should be about 7 volts and a 12 volt car it should be about 14 volts. An alternator will stop charging after the battery is full but a generator will keep charging. So on a 6 volt car it could be as high as 8 volts and for a 12 volt car as high as 16 volts.
If the battery is over charging then turn down the amperage using the third brush. If the battery is too low then turn up the amperage using the third brush.
Ford had the service technicians check the battery hydrometer reading when the cars came in for their 500 mile checkup and oil change. The technician would adjust the third brush according to the hydrometer reading. The third brush setting would change depending on the season and the type of driving the owner was doing. The technician would use a master ammeter and not rely on the car's ammeter to set the third brush.
There are various ways to adopt a voltage regulator to the Model A generator. That way the generator will put out enough to charge the battery and no more and the charging will not depend on whether the car was driven with lights on or only short or long distances. All modern cars and cars built after the Model A era had voltage regulators.
Rotorwrench: Ohm's law pertains to resistor circuits and not to charging batteries because the battery voltage will change depending on the state of charge. Ohm's law also does not pertain to circuits that have coils and capacitors (LC circuits). I am sure you know all this and just made a slip.
If the battery is over charging then turn down the amperage using the third brush. If the battery is too low then turn up the amperage using the third brush.
Ford had the service technicians check the battery hydrometer reading when the cars came in for their 500 mile checkup and oil change. The technician would adjust the third brush according to the hydrometer reading. The third brush setting would change depending on the season and the type of driving the owner was doing. The technician would use a master ammeter and not rely on the car's ammeter to set the third brush.
There are various ways to adopt a voltage regulator to the Model A generator. That way the generator will put out enough to charge the battery and no more and the charging will not depend on whether the car was driven with lights on or only short or long distances. All modern cars and cars built after the Model A era had voltage regulators.
Rotorwrench: Ohm's law pertains to resistor circuits and not to charging batteries because the battery voltage will change depending on the state of charge. Ohm's law also does not pertain to circuits that have coils and capacitors (LC circuits). I am sure you know all this and just made a slip.
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ndnchf
Well-known member
Adding one of Mike Hill's Electronic Voltage Regulators (EVR) is a really clean way to give the original generator fully automatic control. The EVR replaces the entire 3rd brush assembly. I run one in my model A and in my '35 Fordor.
