Aura System Generators

[douglee25]

Has anyone ever heard of Aura Systems?

http://www.aurasystems.com/index.htm

Although it's not listed on their site, apparently they have applications for marine generators/inverters that mount directly to the engine. They use induction vs. brushes so this would lead me to believe it would be ignition protected. They do a lot of government and military work from what the rep communicated to me.

The only downside is that I suppose output is dependent on engine rpm. They quote engine speed to be 1000 rpm - 6000 rpm. I'm waiting on further information.

Thoughts?

Doug

 

[fc3]

Westerbeke's alternators are also brushless. There's special set of windings in the field to excite the rotating windings. Pretty sure that's standard practice.

 

[douglee25]

Westerbeke's alternators are also brushless. There's special set of windings in the field to excite the rotating windings. Pretty sure that's standard practice.

Yeah, I wouldn't doubt it. I more or less was posting as a possible alternative for people who want to install a genset without the high price for a westerbeke. I'm curious how well that setup works.

Doug

 

[RiverRat]

This would only be practical while underway... Don't think to many would want to leave an engine running at 1000 RPM while at anchor for electrical power...

 

[douglee25]

This would only be practical while underway... Don't think to many would want to leave an engine running at 1000 RPM while at anchor for electrical power...

For smaller boats without a genset, it may not be much noiser than a genset? :huh:

Again, just throwing it out there if anyone heard of them.

Doug

 

[fc3]

It might not be much noisier, but I'll bet it burns a lot more fuel. My 7.4s burn about 1 gph at idle. My Westerbeke burns less than that at full load. Pay now or pay later.

 

[r_moss]

One thing I do know is that the system was developed for the Army, so it is probably over engineered. I looked into it for my last boat, but decided against it for some long forgotten reason.

 

[fc3]

Finally had time to fully review the web site. First of all, usability of the web site is awful. Much of the text isn't text, but a photo of text. So no resizing with <ALT>+ or <CMD> +. Stupid design.

There's precious little detail. Looks like the alternator generates power which is converted to DC than inverted to 50 or 60 Hz AC by an inverter. OK fine. It's an inverter. True sine? Doesn't say but claims to be "cleaner" than a genset. So is it sine wave? Who knows? What's "cleaner" mean? It's 80 efficient at 1500 RPM of the generator's rotor. What's that mean? No definition. Stupid. How many RPM does the rotor have to be turned to generate 4KW? 8KW? Doesn't say. Stupid. What's the max RPM of the rotor? Doesn't say. Stupid. So lets say that the max rotor RPM is 7000 RPM. The 32 valve V8 in my Navigator redlines at something like 5500, so it would need a 1.4 drive ratio. If to generate 4KW the rotor needs to turn 3000 rpm, the idle control motor needs to run the engine at 2100 RPM. Not really efficient IMHO.

So in short, what are the hiding behind their crappy, incomplete specs? Or are they just too stupid to put basic data up there?

Best regards,
Frank

 

[douglee25]

Frank, sorry I hadn't seen your reply.

I spoke with the sales engineer who has worked heavily in the design of this system. This system is legit and seems to be very well thought out. Currently they have large contracts with the Army, Coast Guard, and phone companies (service vehicles) to name a few. They are in the process of trying to break into the consumer boating market and are in negotiations with Volvo to sell systems for sub 30' boats.

They have two systems available...

1. A system that automatically switches from the engine driven genset to battery bank via a built in inverter on their control box.

2. A system identical to the above but without the inverter setup.


** Some notes from our conversation...

-The system is a pure sine wave system
-100% efficiency at 1800 rpms
-UL certified, Coast Guard certified, ABYC certified, and NMMA certified

Check out this site which has more info that is marine related...

http://www.turnauraon.com/

Here's one mounted on a Sea Ray no less.

Doug

 

[fc3]

Still doesn't answer the questions. How many RPM do you have to turn the engine to operate a microwave, an air conditioner, or whatever? The army, navy, and coast guard don't care if it's cost efficient. Those guy are as bad as NASA. (No offense, Gary.)

The phone company guys only need AC for short periods of time. So they don't care about engine operation. The military guys are running their engines nearly full-time so they don't care either. On the other hand, if you have to run you engine at 2000 RPM in an anchorage to generate power for your air conditioning and microwave, what the heck are you saving over the cost of a regular genset?

I'm still voting "stupid idea" on this.

Best regards,
Frank

 

[douglee25]

I don't know if there is a linear relationship between rpm and output. I didn't ask them for a spec sheet in that regards. If you want further information, give them a buzz.

Ask for Peter Tabor 310-536-8396

Doug

 

[fwebster]

The problem I see with that system is that it appears to need 1000RPM on your main engine to generate useable output. I've had boats with generators for 20+ years and my experience is that when I use the generator (i.e., I need 120VAC appliances) almost 100% when at anchor and almost never when running the main engines.

While it may generate power, how practical is it to run an 8 cyl main engine @ 1000RPM for your popcorn or to dry Mama's hair.......for me the noise would be a bigger deterrent than the additional fuel burned. I suppose it comes down to a cost vs. value decision for the individual owner, assuming the system is ignition protected.

 

[370Dancer]

No one remembers the Sea Power engine driven genset?
This may be the same stuff, resurfacing now that the inverter side of the equation has gotten better.
I could see using it on smaller boats with no room for a genset in the Southern waters to keep a cabin cool between shore power hookups. I could not see using it at anchorage. I would likely opt for one of the small unit like a Beta Marine, or possibly a Lombardi DC generator and an inverter. Same concept as this, but using a dedicated powerplant instead of the big hulk.