Originally posted by chris229 I really don't care for what some automotive person or book says --------- as the laws of physics are what defines electricity
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.
that mind you is exactly what a cap does----- charge to a voltage and hold. How can current flow from the alternator to the cap if the cap is at the same voltage???
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)
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.
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 "
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. "
just because it doesn't produce a voltage on its own doesn't make it a load. A load MUST sit at a voltage below the current provider---alternator. the study of electricity is been going on for along time and caps are well understood
see above- this has also been clarified.
the battery and alt DON'T work together----- the battery is a load and you were correct the first time when you said it------ unless your seeing the battery as a pimp and the alternator is a Whor*----then in that case they work together
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.....
because the cap is charged to the voltage of the alternator ------- the effect can be seen as if it wasn't there at all --------- because as I said before no current can flow into it
Refer to above- I have clarified myself on this matter.
blah------- don't use autotech books
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.
caps have been uderstood for along time now in electricity---- not something new. Almost everthing you use involves caps. You need to do some research on what caps do and how they work
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.
I fully understand how caps work thank you. Mabey its time you do some research into applied automotive electronics.
hell I wouldn't recommend them either if I didn't know what they hell the did or how they work---------- how could you ------- you couldn't explain how'd they would help
I believe RC put it best:
Richard Clark Writes:"..The audio industry is the only place i know of where you can publish specs that show your product is useless and still be able to sell them------and whats worse is that technically ignorant people will argue against the math!!!!!!!..............RC.."
Perry Babin also:
"This is because there has been some discussion as to whether a capacitor is a help or a hinderence when it comes to keeping the voltage at a higher level than without it. Of course, if you ask someone that's spent more than $100 on a capacitor if it helped, they'll tell you that it has. Why on earth would someone 'fess up' to wasting that much money on 'snake oil'. I've yet to see a capacitor increase the SPL in any system. "
You can reference that right from his site:
http://www.eatel.net/~amptech/elecdisc/capacitr.htm
did you know that alternators & batteries are slow to respond to loads------but that is another thread
I can see this holding true for batteries, however, with alternators- no.
An alternator consistantly supplies power while the engine is running, meaning that there is always power available.
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.
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.
With this in mind- why bother with a cap when the problem can be taken care of at the source?
