Had my new HO alt. tested today................

[jrwalte 10+ year member]

Not only do you need the RPM, but doesn't your electrical system have to cause a demand draw before you see the full potential of the alt? I thought most alts only give out as much power as what is needed, although some HOs could be designed differently.

 

[J31Rob 5,000+ posts]

Not only do you need the RPM, but doesn't your electrical system have to cause a demand draw before you see the full potential of the alt? I thought most alts only give out as much power as what is needed, although some HOs could be designed differently.

so what you're saying is the alternator KNOWS when there is extra stress & starts cranking out more power?

 

[boalova13 10+ year member]

so what you're saying is the alternator KNOWS when there is extra stress & starts cranking out more power?

Lol i think thats what he's saying. Looks like i bought the wrong alt //content.invisioncic.com/y282845/emoticons/wow.gif.23d729408e9177caa2a0ed6a2ba6588e.gif

 

[jrwalte 10+ year member]

so what you're saying is the alternator KNOWS when there is extra stress & starts cranking out more power?

Alts do this by means of the regulator.

REGULATOR

The regulator has two inputs and one output. The inputs are the field current supply and the control voltage input, and the output is the field current to the rotor. The regulator uses the control voltage input to control the amount of field current input that is allow to pass through to the rotor winding. If the battery voltage drops, the regulator senses this, by means of the connection to the battery, and allows more of the field current input to reach the rotor, which increases the magnetic field strength, which ultimately increases the voltage output of the alternator [or amps]. Conversely, if the battery voltage goes up, less field current goes through the rotor windings, and the output voltage is reduced.

Think about it. If the alt just kept producing as much power as it was able to, where would all that power go? It has to go somewhere. And if not, it'll keep increasing the voltage in your car until it damages equipment. This is why some people argue the need for caps. When you have that sudden 'hit' in the bass the power is essentially coming from the battery and then the alt senses, through the regulator, that your voltage has dropped and it needs to give more power. Granted this happens probably in milliseconds, but your alt is still reacting to the power need, whereas the cap has the power the moment it is needed.

 

[jrwalte 10+ year member]

As a real world example, my friend and I tried removing the stock alt from my vehicle to install an HO alt. We 'tried' because we didn't have a high torque socket wrench to get the bolt free. When he connected the wiring back to my alt, he forgot to connect the voltage regulator's harness.

For 2 days I essentially drove around with no alternator. The alt would spin, but because the coils were getting no voltage from the regulator to create the magnetic field they weren't producing any energy. I'm shocked my kinetik battery lasted that long with no charge. I must have drove around for over 2 hours with my music turned up.

I figured out my regulator wasn't connected when my sub amp turned off while driving down the road (kinetik couldn't supply enough voltage to keep it on and it went into protect mode) and my car's performance drasticly dropped, which almost caused me to be in an accident when I tried to make a left turn in oncoming traffic.

Once I connected the regulator the alternator started supplying power and everything was fine.

 

[audioarsonal 10+ year member]

An alt only puts out the current that is required.If the load wasn't enough then you wouldn't get a proper reading.You can't just slap a clamp meter on it and rev it up a couple times.You need to have a load on it as well.Try it while burping at 3/4 and see what it puts out then.

 

[rc10mike 10+ year member]

They did put a load on it with the machine, I seen voltage drop while doing the test.

 

[audioarsonal 10+ year member]

What kind of load?Was the alt on the vehicle?

 

[lilmaniac2 5,000+ posts]

and i bet they put little alligator clips on it to measure the current, theres a reason why we use 1/0 it carries the power.

autozone and advanced can't properly test HO alts //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[lilmaniac2 5,000+ posts]

so what you're saying is the alternator KNOWS when there is extra stress & starts cranking out more power?

yup it does, the actual technical term is a load "excites" the regulator on the alt, IIRC>

 

[lilmaniac2 5,000+ posts]

Lol i think thats what he's saying. Looks like i bought the wrong alt //content.invisioncic.com/y282845/emoticons/wow.gif.23d729408e9177caa2a0ed6a2ba6588e.gif

I guess thats what you get for trying to be a smartass when you have no idea what your talking about.

 

[audioarsonal 10+ year member]

and i bet they put little alligator clips on it to measure the current, theres a reason why we use 1/0 it carries the power.
autozone and advanced can't properly test HO alts //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Exactly.And they have NO idea of the RPM that its spinning at.They just say "yep it puts out but I don't think its a high output"

http://audioforum.termpro.com/topic/22/3982.html

A link as to why.

 

[lilmaniac2 5,000+ posts]

Exactly.And they have NO idea of the RPM that its spinning at.They just say "yep it puts out but I don't think its a high output"http://audioforum.termpro.com/topic/22/3982.html

A link as to why.

I was too lazy to go get dom's link

 

[photocrazy8 10+ year member]

also the later the case of the alt, the more copper they can fit in there----> resulting in more current at idle and max //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[lilmaniac2 5,000+ posts]

also the later the case of the alt, the more copper they can fit in there----> resulting in more current at idle and max //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

It just depends really, If you want a higher max output the curve is steeper and the output at idle is lower, which is one of the reasons Iraggi's larger alts are not that great for daily, because he makes alts that get the boogie woogie down at 2000rpm

I had a 300 amp large case one from him that wouldnt do 50 @ 1200 engine rpm.