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Sourcing Generators
Miks15 - 17/11/11 at 02:18 PM

Hey Guys,
I need a bit of help sourcing a part for a uni project, and you guys never let me down.

I need a generator/alternator that generates 240v. All my searches just come up with complete petrol driven units. I need the Electrical bit and that's all so we can drive it from something else. Any one have any experience with this? All help would be greatly appreciated.

Cheers

carlknight1982 - 17/11/11 at 02:38 PM

How big is the question, equal to a small Honda petrol engine u can get the alternator from machine Mart.
Bigger ones tend to use the flywheel of an engine as the front bearing.
Try mcaltee there close to you as are cummins power generation and Stanford plant.

Miks15 - 17/11/11 at 03:22 PM

We dont actually need to buy one as such, just trying to source details for part of our project. It doesn't need to be a massive one, as it'll be man powered.

owelly - 17/11/11 at 05:00 PM

For a man-powered genny, those at machine mart would do or a normal 12v alternator and an inverter.

carlknight1982 - 17/11/11 at 05:56 PM

bear in mind that the machine mart jobs will need to have a winding speed approaching 3000rpm

i actually work for generator power ltd do a google search and let me know if i can help

SteveWalker - 17/11/11 at 06:03 PM

quote:
Originally posted by owelly
For a man-powered genny, those at machine mart would do or a normal 12v alternator and an inverter.


I presume that 230V ac single-phase is required, if not, I'm pretty sure that car alternators are actually 3-phase ac generators with rectifying and voltage regulating added on. So an alternator with the diodes stripped out will give 3-phase ac, which can be put through a 3-phase transformer or three single-phase ones to give the required voltage with no need for an inverter.

owelly - 17/11/11 at 06:23 PM

Good point. And by altering the field voltage, the output could be altered.

rallyingden - 17/11/11 at 06:25 PM

quote:
Originally posted by SteveWalker
quote:
Originally posted by owelly
For a man-powered genny, those at machine mart would do or a normal 12v alternator and an inverter.


I presume that 230V ac single-phase is required, if not, I'm pretty sure that car alternators are actually 3-phase ac generators with rectifying and voltage regulating added on. So an alternator with the diodes stripped out will give 3-phase ac, which can be put through a 3-phase transformer or three single-phase ones to give the required voltage with no need for an inverter.



YEP ...........
This is how we powerd the electrics on the service barge in my Rallying days, had a second alternator attached to engine.
We lit up a few Welsh forrests when marshalling I can tell you

RD

MikeRJ - 17/11/11 at 07:49 PM

If you want to generate 240v 50Hz from a human powered machine, a 240v alternator is very probably not the best way to go unless the human in question can rotate the generator at a precisely constant speed.

Much better would be a DC generator (or rectified AC) charging a battery which powers an inverter. This can absorb considerable load and speed changes whilst still providing a well regulated 240v 50Hz output.

Miks15 - 23/11/11 at 06:08 PM

cheers for all the advise guys, will bare it all in mind