wierd idea

[666JTK666]

Ok I freely admit I have just woken up and I had this idea or question there is probably some basic issue that makes this a really stupid idea. but I can't think of anything right off hand.
Is it possible to sucessfully run a dc inverter directly from a dc alternator ? I am not talking about crappy low current standard automotive alternators, more like high current brushless alt's.

 

[SternWake]

I Suspect the inverter would not be so happy with the choppy output of an alternator, and would be much happier with a battery in between the two acting as a filter/capacitor.

Also the alternator voltage regulator requires some voltage be present and a source of amperage to power the field.

So could it be done, likely, but would require much much more effort tham using a battery in between the two.

The battery does not have to be huge as long as the alternator is spinning at adequate RPM to power the inverter's load.

https://www.amazon.com/dp/B00KQX5EDO/ref=psdc_15719921_t3_B004JHI8MM

 

[666JTK666]

I Suspect the inverter would not be so happy with the choppy output of an alternator, and would be much happier with a battery in between the two acting as a filter/capacitor.

Also the alternator voltage regulator requires some voltage be present and a source of amperage to power the field.

So could it be done, likely, but would require much much more effort tham using a battery in between the two.

The battery does not have to be huge as long as the alternator is spinning at adequate RPM to power the inverter's load.

https://www.amazon.com/dp/B00KQX5EDO/ref=psdc_15719921_t3_B004JHI8MM

So the battery would act sorta like a powerline filter cap. ok I think I see it..
Yeah this idea does not really have a practical application but the question was just beating on my brain..
thank you.

 

[John61CT]

With a large enough inverter load relative to the alt output, you'd want better than crappy, good enough to act as an effective buffer when the former is peaking or when you need to refuel.

 

[Weight]

Is not that how a Honda 2000i generator works? And other inverter generators.

 

[Mobilesport]

I always thought alternators had a clean DC output , I thought that was one of
the reasons for all the diodes.

 

[John61CT]

Is not that how a Honda 2000i generator works? And other inverter generators.

Yes, and the tight integration between the inverter, alt output electric regulation and motor electrics is a major cost component.

 

[John61CT]

I always thought alternators had a clean DC output , I thought that was one of
the reasons for all the diodes.

Not black and white, gradations of "clean", both on the alt output side, and how much input variation the inverter will tolerate.

 

[VJG1977]

Here is a good explanation of how a charging system works.  http://www.bcae1.com/charging.htm  About one third of the way down the page is an illustration of the output waveform.   The diode bridge does rectify the three phase AC to DC but there is a small ripple.  The frequency of the ripple depends on the RPM that the alternator is spinning. The battery does act as a buffer and filter to help smooth this out.  

There are companies that sale high output alternators with mounting brackets for many vehicles.  Google high output alternators.  I've seen 300 amps at idle advertised.  

There are a couple of threads that discuss adding a second alternator to charge house batteries.

 

[John61CT]

There are companies that sale high output alternators with mounting brackets for many vehicles.  Google high output alternators.  I've seen 300 amps at idle advertised.  

Lots of scammers in that market, a custom winding in a small drop-in frame may not last very long actually putting out anywhere close to its supposed rating.

Much better if at all possible to get a creative auto electric guy to figure out how large a stock large-frame Leece Neville high-output amp can be fit to your engine, up the pulley ratio a bit to output big amps at low RPM. Much more robust solution.

But only if you're actually driving hours per day. A little gennie will be cheaper than idling your vehicle if you're stationary for days.