Calling B.S. on all these HO alternators

[MakeshiftAudio 10+ year member]

I know we dont use current shunts for load.. The main 1/0 output wire does run through a 500a shunt which is where the ammeter on the bench gets its feed...
Honestly, I dont remember what the final ohm load is... The big first stage bank is made of big "corn cob" resistors that are ~30 amps each @ 12v and 60 @ 24v, but I cant remember what resistance they are, I would honestly have to look.. The second bank I use is actually FET's, not resistors.. Just dumping output to ground through the FET's creating load, and the third stage is actually about 100 2w (size) resistors, but again I honestly dont remember what resistance they are...

The 30A@12V would be .4 ohms each.

Must be a large bank of fets or some beefy fets with some current limiting resistors.

Yeah, nice bench setup, though the signal you feed the fets are fed on a duty cycle I'm sure, but how is that duty cycle determined?

 

[DC_Power_Rob 10+ year member]

The 30A@12V would be .4 ohms each.
Must be a large bank of fets or some beefy fets with some current limiting resistors.

Yeah, nice bench setup, though the signal you feed the fets are fed on a duty cycle I'm sure, but how is that duty cycle determined?

I actually think they are .5 ohm @ 12v because *techincally* they are about 27.5-28 amps per.. If you look at the bench, that is what the 5 toggle switches are for..

Well, yes and no on the FET's... The FET's are either on or off, it's just how many are on at any given time.. We have a big 3K pot that turns them on, more resistance = more FET's come online.. They are fairly beefy FET's, but we do have to replace a few now and again... FET's aren't designed for that kind of use, but they work in this case..

 

[MakeshiftAudio 10+ year member]

Yeah, that's what I was asking about in regards to duty cycle. When I originally said it I meant a higher freq (20khz+) PWM duty cycle.

Have you thought about using IGBTs instead? At these currents it would almost be better, it would be I*forward voltage of the IGBT compared to I*I*Vds(on) of the FET.

I would highly recommend you the CM300 or equivalent models though they're meant for higher voltage applications like normal IGBTs(600V or 1200V max voltage ratings), if you're able to drive them. They're in the IGBT brick package, and do not cost too much if you know where to go to. I've used the CM600 series for years with only a couple of deaths due to physical design flaws... Which usually end with a pile of molten copper from pulsing ~1000A into a short. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

Generally a rant, but depending on how often you replace the fets, it may save you money. IGBTs and FETs can be changed 100% in each other's place most of the time. It only really matters on the driving freq and the ability to drive the brick. If you have many fets on one side of the bridge, you might be able to drive them.

My random 2 cents in regards to load switching.

PS: Shorting to ground is done all the time, called a SMPS, but you're switching it through the windings on a transformer to ground. Instead of having an inductive load you have a resistive load with your bench test. That's all.

 

[MasterOfAllBass 10+ year member]

i love my dc power alt



It dose rated power

200 @ idle

 

[headlesskoopa 10+ year member]

i love my dc power alt

haven't installed mine yet, but it looks like a great made product //content.invisioncic.com/y282845/emoticons/veryhappy.gif.fec4fed33b4a1279cf10bdd45a039dae.gif

 

[MasterOfAllBass 10+ year member]

haven't installed mine yet, but it looks like a great made product //content.invisioncic.com/y282845/emoticons/veryhappy.gif.fec4fed33b4a1279cf10bdd45a039dae.gif

Yes it is! //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[Annnarbor84 5,000+ posts]

Sent you a pm Rob. At least there is some good info coming from this thread....

 

[slim2fattycake 10+ year member]

I don't see how Rob is the only guy defending his own car audio HO alts and no other company is here. I guess Rob can back his stuff up.

I will be getting the new 230 amp HO alt from Rob soon. I can get with snoopdan for him to test it as well so there will be an outside test for everyone to see the truth.

Rob, I haven't heard from you in a while. This is Phi.

 

[DC_Power_Rob 10+ year member]

I don't see how Rob is the only guy defending his own car audio HO alts and no other company is here. I guess Rob can back his stuff up.
I will be getting the new 230 amp HO alt from Rob soon. I can get with snoopdan for him to test it as well so there will be an outside test for everyone to see the truth.

Rob, I haven't heard from you in a while. This is Phi.

Phi, I will send you a PM... The 230 your getting is the baby brother to the 270 (as I mentioned to you)... The 230's will all run closer to 250, and a shade under the 270 at idle.. Feel free to have Snoopdan test away.. I'm doing an install on an Accord this week, I guess I'm going to have to do a video of that one too.. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[snoopdan 5,000+ posts]

I'm glad ive been volunteered. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[slim2fattycake 10+ year member]

Yup. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[dB-r 10+ year member]

Thank you Rob so much for coming here and defending your product. Your now the guy I am going to send ALL of my customers to for alternators. You know your shiz!

Just to be clear. I didn't start this thread attacking Rob or any other manufacturer of these things in particular. I have just heard a couple bad results with so called HO alternators, and since I had seen some bigger alternators make less power in the past than some of the claims of these smaller case alternators outputs I started this thread.

If Rob has the balls to come in here and defend his product this way, and answer technical questions when the "technical" people that are here (thank goodness for them) ask him, then he is confident, knows what he is doing, and sounds like he will stand behind his product and his shop doors are always open as he says, he even said you could bring your own test equipment I think, so yeah, I think this guy would be who I would recommend.

BTW: Rob, while I don't want a small case alt from you, I am going in September to pickup a truck that I will be using 2 compete in 2010 season with, doing the build this fall/winter and I want 2 large case badass alternators from you. Will be in touch, and believe me gonna send all my customers to you. Also, there was a guy at the USACi show running one of your alternators and his shit was kicking *** so I have seen it in person too. Good deal. As for the rest of the HO alternator companies out there? Well, people have posted in this thread their experiences, I would recommend before you drop your hard earned $$$ on a product that sounds too good to be true, read through this thread, google the company that makes the alt, read reviews, basically do your research before you give them your money. That's what I do.

 

[98HOEONSIXEZ 10+ year member]

x2 that video is meaningless to me since they didn't bother to have a tachometer alongside the ammeter and volt meter. Actually, it's pretty stupid they didn't do that since that's the referencing factor in the test //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

You like apples?

http://www.youtube.com/watch?v=oigS8ccj6oA

HOw you like theM?//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[dB-r 10+ year member]

Nice vid.

 

[snoopdan 5,000+ posts]

You like apples?
http://www.youtube.com/watch?v=oigS8ccj6oA

HOw you like theM?//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

That is a better test setup, but still not complete since there is no way (at least visible in the video) to induce a real world thermal environment. Im also pretty sure you have no idea what i'm talking about since you posted the link in some way to prove something that we've already discussed in some length in this thread.