Generator vs. alternator

[Jethro]

I am considering adding work lights to my B1550. I read on another thread that the newer tractors come with an alternator that will handle such additions rather than a generator. The wording implied to me that it was not a good idea to add additional lights to a generator.

Any body have any insight into this?

 

[B2400]

As long as you don't exceed the output of your generator you shouldn't have any problems. Watts divided by volts= amps. ie.. 35 watt bulb divided by 12 volts=2.92 amp draw. Your system may put out slightly more voltage than 12 but this leaves a little margin for safety. Once you exceed your generators capacity, you begin a drain on the battery. This would be OK for short durations with charge time in betweem but it's best to avoid it. BTW, I believe your generators output is around 14A.

 

[Dan239]

First of all an alternator is a generator that produces alternating current called AC. Old cars had what was called a generator and produced direct current called DC which fed the system to keep the battery up and supply other items with DC.

In a modern car the generator produces AC and it is then converted to DC through a rectifier using diodes. The system must have DC to operate. However the DC produced this way is not a flat voltage but is actually a pulsating DC which is smoothed out by the battery maintaining a steady voltage.

The reason cars and trucks went to AC generators is because the brushes now only need to sustain a field in the armature which is a lot less current [amperage] than what is needed in a DC generator. In a DC generator the brushes had to carry the full load of what was being produced and they would not last very long.

The term alternator came into common use to describe a generator which produces AC and then converts it to pulsating DC.

I hope this is not too much more than you wanted to know, but I know most people do not realize that an alternator is a generator going by a different name. Some modern parts list will still refer to the alternator as a generator.

I know this probably does not answer what you are trying to determine, but all modern generators are of the AC type because DC generators could not easily produce the needed wattage for today's applications.

What you need to determine is if your generator, or alternator if you prefer, can maintain the needs of your system as pointed out by B2400 in the previous reply.

Daniel

 

[MadReferee]

Kubota refers to their stock 14 amp generator as a dynamo. No real difference. Both need the external rectifier. The 40 amp alternator option requires no extenal rectifier which is usually left mounted when the alternator is installed because it is difficult to remove.

 

[Chris_in_Oz]

Simple -

If they say it's a DYNAMO, then it's DC.
If they say it's an ALTERNATOR, it's AC.
If they say it's a GENERATOR, it could be either, depending whether the "generator" is a Dynamo or an Alternator.

How many of you have petrol generators that have AC (mains) outputs and have 12v (DC) outputs? That's just fine with a "Generator".

As long as you know what you want, don't worry if the dealer doesn't know what he is talking about - just remember it before believing him!

 

[Jethro]

As long as you don't exceed the output of your generator you shouldn't have any problems. Watts divided by volts= amps. ie.. 35 watt bulb divided by 12 volts=2.92 amp draw. Your system may put out slightly more voltage than 12 but this leaves a little margin for safety. Once you exceed your generators capacity, you begin a drain on the battery. This would be OK for short durations with charge time in betweem but it's best to avoid it. BTW, I believe your generators output is around 14A.

Thank you for your reply. This answers my question. It is good to know the definition of a generator and an alternator, but that was not my main concern, although the title contradicts that. My tractor has a dynamo. I just wanted to know if I could safely add work lights. Thanks to all of you for your responses.

 

[David_Kb7uns]

Simple -

If they say it's a DYNAMO, then it's DC.
If they say it's an ALTERNATOR, it's AC.
If they say it's a GENERATOR, it could be either, depending whether the "generator" is a Dynamo or an Alternator.

Just looked up on Wikipedia and they term a DYANMO as a device with a rotating magnet, which the Kubotas do come with and thus are not DC but AC verses an ALTERNATOR that has a rotating FIELD that has an intensity controlled by a voltage regulator. And I think the generators have the stationary field with the rotating windings with brushes carrying the charge current.
David

 

[Dargo]

First of all an alternator is a generator that produces alternating current called AC. Old cars had what was called a generator and produced direct current called DC which fed the system to keep the battery up and supply other items with DC.

In a modern car the generator produces AC and it is then converted to DC through a rectifier using diodes. The system must have DC to operate. However the DC produced this way is not a flat voltage but is actually a pulsating DC which is smoothed out by the battery maintaining a steady voltage.

The reason cars and trucks went to AC generators is because the brushes now only need to sustain a field in the armature which is a lot less current [amperage] than what is needed in a DC generator. In a DC generator the brushes had to carry the full load of what was being produced and they would not last very long.

The term alternator came into common use to describe a generator which produces AC and then converts it to pulsating DC.

I hope this is not too much more than you wanted to know, but I know most people do not realize that an alternator is a generator going by a different name. Some modern parts list will still refer to the alternator as a generator.

I know this probably does not answer what you are trying to determine, but all modern generators are of the AC type because DC generators could not easily produce the needed wattage for today's applications.

What you need to determine is if your generator, or alternator if you prefer, can maintain the needs of your system as pointed out by B2400 in the previous reply.

Daniel

Clap, clap, clap! When I began restoring old muscle cars I had to decide whether to rebuild the generators or replace them with alternators. With the demand of modern engines (like the 572 ci 720 hp crate engine), the power demand increases. Not just for the engine, but for all the gauges, rev limiters, but for high energy ignition systems and Vintage Air A/C systems. Before I asked questions and did some research I didn't know the difference. All I knew was that the alternator would eliminate the extra "box" that sat on the inner fender well that was part of the system, which looked to be a PIA. So, it was fairly easy to just go with a single wire 100 amp polished aluminum alternator; not cheap, but easy and effective. Anyway, good explanation.

 

[RollingWoodFarm]

Not sure you ever got an answer. I'd like to know as well before I add work lights to my B1550. I think I may just put LED's on the top of my cab and install a switch between them and the headlights, which aren't much good anyway.

 

[Paystar]

My B2620 came with the 14.5 Amp Dynamo. Dealer added two front work lights and one rear and said I would be fine. But I did end up getting the 40A alternator installed since I will be doing lots of night time work and didn't want to take a chance of discharging the battery. Figured it was cheap insurance.