Capacitor or no?

[chris229 10+ year member]

It never ends

Originally posted by zane Hrmm.. politely kick your self in the shennanigan. Automotive Electronics have everything to do with what this discussion entails. If you do not care about what is common knowledge and instruction in the automotive world then continuing this discussion is pointless, as you will not be able to grasp anything from here on out. However, if you still would like to insist that my ASE manuals for Advanced Automotive Electronics, and Mitchel Repair Manuals are just a bunch of BS; I guess you had better get busy informing all the mechanics across the globe, that what they have learned is all wrong.

whens the last time you heard of someone consulting a mechanic on electrical power supplies-------- i don't
as they are the same people who claim caps blow your alternotor and to add more batteries

telling that you need to change the ECU when it was just the distribitor

tell you you timimg is advanced 45 degrees BTC and telling you they fixed it------- when starting a car at 45 degrees would be imposible----------- so then you realize they must have forgot about the timing spout ---------

I was unclear in my previous post. Sorry for the confusion.

The cap would be a load only when its voltage falls below 14.4 volts. (Car at idle)

nope------- if the alt fell in voltage at idle the cap would turn into the current source than fall to the alternator voltage -------- never at any point in this time becoming a load---------------- rip that page out of your autotech book----- it's bad info

However, as a cap only contains enough reserve for a second or two, it is useless after that, and becomes a load on the charging system more often than not.

tha amount of reserve is dependent of the current draw------- when ever the alternator recovers so will the cap

You can referecnce this tech article on rec.audio.car

"Although a battery may be able to respond in tenths of a second, bass notes are often much shorter and need current immediately -- which capacitors can supply. The difference between the two is that while the capacitor can supply a large amount of current immediately, their voltage quickly drops making them ineffective " in that time the alternator would have recovered ---- if listening to music--------- a cap serves to reduce power supply impedance at the amp and it is a benifit that it is always charged to the highest source voltage

http://www.mobileaudio.com/rac-faq/rac-faq_2.html#SEC23

Or from http://www.eatel.net/~amptech/elecdisc/capacitr.htm

"Keep in mind that the discharge is only for a fraction of a second. The capacitor can not act like a battery. It only serves to fill in what would otherwise be very small dips in the supply voltage. "yes it not a battery and that is why you want one---- the stiffen the voltage to the amp and smooth the load to the alternator--------- with a cap at the amp you can reduce the power wire size to the trunk from the battery --- cause huge current draws are no longer sent down the power wire-------- does you autotech book tell you that?

They do work together. In simplest terms, Each is the sole power supply while the car is not running or running respectively.

Yes, while the vehicle is running, the battery is a load. It is not a load when the vehicle is not running.

All components of the charging system work together. This is common auotmotive knowledge.....

you don't really think id didn' know the battery is the current source with the car off do you?-------- when the car is runing the battery works against the charging system -----cause of it's size[cca]------ it would be better if it could be reduced as to lighten the load on the alternator BUT it can cause it must start the car in all temps

So all mechanics are wrong now?

Blah- Mabey you need to take a look into some automotve tech books, as this issue does pertain to automotive electronics.

ok i'll go ask my nearest mechanic what ESR cap I should get for a high current application and how many farads---- also maybe I should ask him ---------as he seem to really be a electricial engineer W/ physics background ------ how much current capacity is need for my my sysytem when playing music the has a 10/1 ratio

I agree- caps have been arround for a long time and are extensively used, however, thier purpose is never to supplement a weak power supply.

it stiffens it----caps are used for this purpose everywhere

I fully understand how caps work thank you. Mabey its time you do some research into applied automotive electronics.

---------why

I believe RC put it best:

[/b][/color]

someone just did this last weak----
I REALLY hate people who quote some else saying something ----------- without PUTTING THE WHOLE THREAD

if really wanted to I could make you appear to say something you didn't too

I have you know that ----------------------------------------------------------------------------------------

RC was the first to use cap on the power supply to and amp for stiffening benifit

He was the first to work with a company to market LOW ESR caps

He has done many many tests with a graphing scope to show the benifit

the thread you make sound like ----- he is saying caps are useless ------ is REALLY talking about HIGH ESR super caps-------------- but make it sound how you want it doesn't change the laws of physics

if you would glady post the whole thread that would be nice --------------so we can see how lost you are------------ let me know when your drowning-----------

Perry Babin also:

[/color]

You can reference that right from his site:

http://www.eatel.net/~amptech/elecdisc/capacitr.htm

k---------i'll go check out this guy------- who is lost too. There is no disscussionyou can do the test with a scope---------- it stiffens thats what caps do that what they are know to do----------thats why poeple use them----------not just in car audio EVERYWHERE ------they stiffen---------- it's so simple BUT so hard for you to understand

I can see this holding true for batteries, however, with alternators- no.

open your auto tech book to section 10------------------alternator field current------------- how does the alternator adjust output? how often does it do so? lets see if your autotech book gets that right----------K

An alternator consistantly supplies power while the engine is running, meaning that there is always power available.

well yea but no too---- lets see how you do on your test Question

There are some alternator Voltage regulators that will not react as quickly as most do today-however, I would certainly not classify a fraction of a second as slow. So long as there is sufficient power to begin with, this should not be an issue.

extremly slow when the amp is swiching -------------------high speed----- talking------ drag car fast---- maybe the autotech book can ref that term for you ------------- they switch @ 30KHZ-100kHZ ----- so is that alternator so or what

Only when you require more than the charging system was designed for will you notice any "lack of response." This is because the alternator can not keep up with the power demands. Adding a cap that will "alleviate" this strain for a matter of a second or two will still not solve the problem. Once the cap is out, it too has to wait for the alternator to respond. Makes caps pretty useless, that is - unless you have a whole truckload of them behind you to make sure that the alternator does not get over burdened.

really----------- you should stop reading those books--------------- the boats leaving without you

With this in mind- why bother with a cap when the problem can be taken care of at the source? [/b]

---------------- ohhh sh*t --- what's your fix-------- got to hear this

 

[chris229 10+ year member]

zane if I sound pissed don't mind me------------- I just get worked up when poeple claim this and that when it's has been known along time how something works

it's not you really either------just the handed down BS lines and info i hear time and time again------ like I don't know what i'm talking about

people find me and chalange me ALL the time about the same stuff-------- cause that what they HEARD-----------

you know what I say--------- a simple test PROVES it

just got to find a graphing scope

 

[zane 10+ year member]

I am posting this here only to inform those who may come across this thread at a later time.

This discussion has been continued here:

http://forums.caraudio.com/vb/showthread.php?s=&threadid=15196

Please go to the above thread for the correct information. This matter has been cleared up and caps have been proven in-effective.

I will no longer continue to post on this thread. Please refer to the above thread.

Thanks!

-zane

 

[jlaine 10+ year member]

This fellow cracks me up... //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif