- Joined
- Aug 15, 2007
- Messages
- 1,613
- Reaction score
- 46
- Points
- 48
- Location
- toenails of foothills NW of Atlanta
- Vehicle Year
- 1985
- Make / Model
- ford
- Engine Type
- 2.3 (4 Cylinder)
- Engine Size
- lima bean
- Transmission
- Manual
- 2WD / 4WD
- 2WD
- My credo
- vertical and above ground
AlanD:"Why do alternators even need an OFF switch?
Because they can act as an electric motor, if you leave them connected to power, the rotor part, they will try to spin the fan belt, and of course they can't, lol, and this will drain the battery pretty fast."
Alan, how does a 'slip ring' rotor work as a motor if it is fed DC voltage? Don't DC motors need a commutator with individual bars for each of the windings on the rotor? I knew old generators could be 'motorized'(and you had to touch power to the field(?) when you installed a re-man to polarize the electromagnet- been a Looonggg time)
All I know about the warning lights fits what you said, except I hadn't heard about the warning light providing the exciting current for the field(right?). I thought the light was in parallel with a 'shunt', but never dug into the details, just accepting that...
I remember on old vehicles my dad set the idle low enough the generator light would flicker or glow dimly(or brightly, depending... it's been a long time) as it was provided a potential difference(voltage) across the 'ground' case and the 'B+' pointy end. If the generator was cooking properly, it was V vs V butting heads, mental image, and the light did not light. I sort of remember if you had some bad windings in the rotor, you may get a dim glow even with the engine running at highway speed. Boy, that was a while ago.
tom
Because they can act as an electric motor, if you leave them connected to power, the rotor part, they will try to spin the fan belt, and of course they can't, lol, and this will drain the battery pretty fast."
Alan, how does a 'slip ring' rotor work as a motor if it is fed DC voltage? Don't DC motors need a commutator with individual bars for each of the windings on the rotor? I knew old generators could be 'motorized'(and you had to touch power to the field(?) when you installed a re-man to polarize the electromagnet- been a Looonggg time)
All I know about the warning lights fits what you said, except I hadn't heard about the warning light providing the exciting current for the field(right?). I thought the light was in parallel with a 'shunt', but never dug into the details, just accepting that...
I remember on old vehicles my dad set the idle low enough the generator light would flicker or glow dimly(or brightly, depending... it's been a long time) as it was provided a potential difference(voltage) across the 'ground' case and the 'B+' pointy end. If the generator was cooking properly, it was V vs V butting heads, mental image, and the light did not light. I sort of remember if you had some bad windings in the rotor, you may get a dim glow even with the engine running at highway speed. Boy, that was a while ago.
tom