Exactly what does a capacitor do

From my physics teacher and my own readin, I have come to the conclusion that a cap will hold a certain charge until it is drained by a source which needs that stored charge it had.

People say caps dont work, they just dont know. I always ask these people who preach caps are useless how many microfarads of capacitance thier amp has, they usually dont have anything to say after that. They dont know theuses of caps. Its really a shame.

 
Yah, they seem pretty nice to me. Ima get this 1.2 Farad cap off ebay for 50 bucks shipped. Oh and it has pretty lights! (jk, i dont give a **** about lights) although they are pretty //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 
"Giving it time to charge up"...ever discharge an electrolytic cap before? Do you have any idea how fast they discharge to a zero voltage state //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
indeed i have. usually for fun at that.

one of my major concerns with caps in a car audio setting as opposed to a typical setting is the lack of rectification. basically from an electrical standpoint the cap will provide power to the amp AND to the battery as needed. the voltage at the battery starts to drop, the capacitor will attempt to send current towards the battery AND run the amp. this results in an even faster discharge time.

 
Unless you could find a Zener diode rated for...oh, a few hundred amps //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I'd love to see one of those. The voltage drop across a diode that size would probably not make it worth it, though.

indeed i have. usually for fun at that.
It's fun...if you're expecting it //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif When your screwdriver slips and shorts between the terminals, it ain't so fun, hehe...

 
so are caps better then batts?

80

i want to see scottie j run all those mt12's and instead of using batts use caps..i want to see if it will work..................lol....just trying to prove a point

 
so are caps better then batts?
Better than batteries? For what? //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

If you're trying to start a car, then no, I wouldn't recommend using a capacitor //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

On the same token, if you're designing a crossover, I wouldn't recommend using a battery in the Zobel network...//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

You could think of a battery as nothing but a capacitor with a sluggish ESR and time constant and loads of capacitance...but each have their purposes.

 
Unless you could find a Zener diode rated for...oh, a few hundred amps //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I'd love to see one of those. The voltage drop across a diode that size would probably not make it worth it, though.


It's fun...if you're expecting it //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif When your screwdriver slips and shorts between the terminals, it ain't so fun, hehe...
best i can think of would be some kinda BJT circuit. at 100A, you really can't hope for the famous silicon 0.7V forward drop. off top of my head, it may be possible to get a few diode connected BJTs to give about 1V of drop... if you can get a higher voltage then the battery noramlly has, you might be able to reduce this a bit.

trying to think of what a MOS device would do. don't think it would work too well either

 
best i can think of would be some kinda BJT circuit. at 100A, you really can't hope for the famous silicon 0.7V forward drop. off top of my head, it may be possible to get a few diode connected BJTs to give about 1V of drop... if you can get a higher voltage then the battery noramlly has, you might be able to reduce this a bit.
trying to think of what a MOS device would do. don't think it would work too well either
Looks like jack found a new friend.

all that technical jargon...

 
Looks like jack found a new friend.
all that technical jargon...
yes. and i even get the single-ended triode > solid state quote. the avatar is a single triode, though i've seen more dual triodes really. recently got my BS degree in electrical engineering, going for my master's. i do a lot with analog and digital components. most of my inspiration has come from car audio amplifiers -- SMPS and Opamps, crossovers, into DSP and such. i'm wanting to get a job with RF on IC stuff.

 
My hero...//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif I don't have the math skills for the BSEE...yet. So I content myself with heckling the lesser-technically inclined while stumbling my way through a degree...once I decide what that is...

the avatar is a single triode, though i've seen more dual triodes really.
You can read a schematic...better than 95% of this forum, who wouldn't know a cathode follower or the difference between a MOSFET or a JFET if it came up and bit them in the ***.

i'm wanting to get a job with RF on IC stuff.
Another hobby/money pit of mine is amateur radio...I don't mind working on that, as long as it's under 2.4GHz or so, and it's not SMD //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Me and SMD don't have a very good relationship.

 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

About this thread

Foote

10+ year member
CarAudio.com Elite
Thread starter
Foote
Joined
Location
Horn Lake, MS
Start date
Participants
Who Replied
Replies
28
Views
3,905
Last reply date
Last reply from
vosschs
IMG_20260513_214311575.jpg

ThxOne

    May 13, 2026
  • 0
  • 0
IMG_20260513_213956814.jpg

ThxOne

    May 13, 2026
  • 0
  • 0

New threads

Top