AC or DC alternator

Just a snippet of info!
In Antwerp Belgium I found a big store that supply,
Washing machines/Tumble dryers/Vacuum cleaners/Pumps/Everything you can think of all 24v/36v?
It is where all the barges in Europe get there stuff and 24v is better all round for most boats plus you can easily split 12v for your requirements.
This may be a simpler solution, You guy"s need to get out more.

Pistobroke Do you know Ennzo Rossy

 

There is a big sore in Antwerp Belgium that sells everything you can think of all running on 24v/36v, Its where the barge's get all there stuff.

You guys need to get out more. (Pistnbroke do you know Enzo Rossie)

 

Copper
Do you have a name or web link?

 

Powerabout I think you will find that if you keep the throttle on one setting on a diesel the govener will vary the fuel to maintain that RPM even as the load varies . which is fine for the application in hand ....

No enzo Rossie in my life ..what have I missed ??

 

Pistonbroke
One question..
If your cruising along in a diesel truck and you get to a hill does it slow down or does it go up the hill at the same speed assuming you leave your foot in the same place?

http://www.woodward.com/engine/diesel/diesel2/governors.cfm
http://www.tpub.com/content/construction/14264/css/14264_165.htm
http://www.waybuilder.net/sweethaven/MechTech/Automotive01/default.asp?unNum=4&lesNum=4&modNum=5
There's isochronous (constant speed) and there's variable speed

 

you misunderstand ...if the truck engine has sufficient power then you stay at the same speed but usually they dont have sufficient power ...////this guys 28hp diesel will have loads of surpus power to drive a 3 kw generator so it will stay at say 1500 rpm as loads vary .....trucks are not lightly loaded stationary engines ....

 

Prices for inverters keep falling, especially for non-namebrand non-sinewave inverters (which are ok for most uses). Some are about the same $/watt as generator heads and they are certainly easy to install. But be careful, most inverters can output 2x starting currents, but many electric motors need 5x (so you need to oversize the inverter).

I agree that an engine needs a rpm based governor for a normal AC generator head.

 

For my solar powered backup system I use a 2 Kw inverter, now approx. 12 years old. Expensive at the time, now it costs just a few 100 $$.

To get rid of the annoying hum in electric motors, especially the synchronous ones, I've added a 20$ filter with 2 toroids and a capacitor, works like a charm.
It takes the sharp edge off the waveform without drawing noticeable current.

 

I assume you use a stepped square wave inverter.

 

Take cheap stepped-square inverter, add big LC filter, save $600.... I like that one, CDK

powerabout, pistnbroke - the generators that Simon is interested in are not fixed-frequency types, they produce constant voltage at any RPM (but reduced current/power at lower revs). They produce 3-phase 250 volt AC at whatever frequency the thing is spinning at, which is then converted to 1-phase AC at 230 volts, line frequency (50/60 Hz) by a circuit similar to that found inside an inverter.

 

Marshmat
Ok then perfect for a main engine then.
Cheers

 

Some like to call it synthesized sine wave, but you are right Gonzo.

 

marshmat ..only some of the generators refered to were multi speed but the first chinese one was 1500 rpm/4 pole ...would you prefer to keep the rpm constant whislt you do the washing or rely on all that electronics.?? .I have at least one big inverter will all its MOSFETS blown in a chain reaction meltdown

 

In my opinion, all things considered and depending on exact details, it is a toss up. But I would definitely favor an inverter for smaller loads.

 

A fringe benefit of the LC filter is that it softens a short circuit allowing the overload circuit in the inverter to cut in before the Mosfets are damaged.
The same principle is used in inverter welding equipment.