Power capacitor 1-4 farad for car amplifier

[ggroup]

Mr.V [email protected]
hi, any one can help me for webs or forum have information about capacitor very high capacity 1-6 farad.
Planing to enter this kind of this cap, but can't find how to handle it. it like very big batt. .
how to charge and discharge, how to test, how to prove it's advantage
thank vidhya s. bangkok thailand
if you have change to bkk i will buy you one nice thai food.

[ele1200]

Wow.....wouldn't a 1 farad cap be very, very big???

[russlk]

Panasonic makes low voltage capacitors up to 50 farads, working voltage 2.3 VDC. Check out their web site and look for SD series or HW series gold capacitors.

[Dimbulb]

I am not sure how much I can contribute to this discussion. <p>I have read that in some high end automobile stereo systems some use a set of stiffening capacitors in their trunk mounted next to some high perfomance bass woofers.<p>I think that the capacitors release current that move the large woofer coils with sufficient air movement to win a stomper bass contest.<p>exactly how they connected has been unclear to me and emails to the companies selling them refuse to reply. I think they are triggered by a secondary amplifier (600 watts) that has been fed a well filtered bass signal from stereo up front.<p>Also from what I have read you want the back side of the speakers to output the bass into a resonating cavity where the final percussion is released from short tubes about 6" by 4" long.
If the front of the speaker is used it tends to cancel the waves. <p>Your ears can be permanently damaged and/or the windows in your neighborhood may vibrate to much. You must be responsible for the percussions you release at this magnitude.

[MrAl]

Hello,<p>Some of these are called "Super Capacitors".<p>--Al

[Joseph]

Those Panasonic capacitors mentioned sound like air-gel types. I figure those could be put in series, but have not actually tried to see if it would work.

[Chris Smith]

What is the "baht to farad" rate these days? <p>Actually a lot of stereos use a Large farad cap at the [+]power-in circuit intake of the bass amp to stop the power surge that bass units require for "quick" drain purposes. It supplies amperage to the amp up close, instead of requiring large wires to supply quick response to the amp. When you place the amp in the trunk, ten feet of heavy wire supplying the amp wont respond properly to the voltage drop and if the voltage is lowered at the amp, even momentarily, the distortion levels of that amp will suffer greatly. Some place small batteries in the trunk, but this also has draw backs. Usually one or two farads at a 18v rating, is sufficient to do the trick.

[ggroup]

Dear Bieber Ca.
The purpose for this capacitor exactly that you explain.
The thing that I worry for the new cap, is it charged? If not and start to service by direct connect to battery look like we short-circuit the batt. I think we need some resistor in series to charge be for service.(what the value and how long)
If the service garages don’t know we the Cap. In trunk and need to remove the car battery and install again,
What well be happen?
I am planning to import 1-2 farad from Korea and China for Thai market. (The competitor not so many in this time) Any idea to test value, leakage, loss, inductance, and how to convince and prove the customer for the advantage of the thing?
The Korea give some spec for the storage time 1 year !! When I ask back said something like the voltage or capacity will change if keep for long time.
90% of this cap. are 1 farad in Thai market.
The prices 3,000-6,000 (with digital meter) baht depend on brand and shop. 1 US$=33.xx baht

[Chris Smith]

The quick answer for now is ...It appears to short out because of its size. Its like one dead battery, connecting to a good battery, but aside from the spark factor, and the apparent surge, I would simply charge it through a fifty or one hundred ohm power [100watt] resistor to get it up to speed and voltage, and then by pass that resistor when in operation. Some caps don’t like “Surge” intake or discharge like attaching them to the battery, or shorting their leads.<p> This should take care of that.<p> I might also short the two leads [+&-]out through a 100,000 ohm resistor [1 watt] {Permanently} to discharge it when the battery is disconnected and left alone so no one gets a surprise in the future. These low leak caps store a charge for months! <p>Also a large blocking diode in line between the battery + and cap + will stop that special surprise for the mechanic who disconnects the battery up front, and the cap is still fully charged for a while, should he short out the battery lead or alternator? <p>Ten minutes later the cap will surly discharge if there is a 100,000 ohm resistor across its leads,...to drain it. The drain is small, but it will discharge the cap for safety sake.<p> Boy, the baht rate is up, its was only 20 baht per buck when I last visited Bangkok, back in the dark ages? How is Chang Mi these days? Still Quiet?

[Chris Smith]

PS....The charge time through the resistor is <p>"as long as it takes"<p> .....and when the cap and the battery are at the same voltage.<p> Then by pass that charging resistor and connect the Caps power lead [+] directly to the battery voltage wire.

[Chris Smith]

I am planning to import 1-2 farad from Korea and China for Thai market. <p>This is a good size for your job,...1 to 2 farads. <p>Any idea to test value, <p>A digital Cap meter is the only good way, or you can applay a voltage, charge it up, and apply a drain value, and count the time, the old fasion way? <p>
leakage, Leakage? <p>A volt meter over time? <p>loss, inductance, <p>For your purpose, these factors don’t matter, unless the cap is completely shot? <p>how to convince and prove the customer for the advantage of the thing? <p>Bass response will suffer when the voltage drops below specs. Use music that is “heavy” in bass to show the customer? A volt meter [non digital] can show the swings and peaks to the customer, but the “music” with lots of base, should be the “show case” or example. <p>
The Korea give some spec for the storage time 1 year !!<p>That’s why you place a 100,000 ohm resistor across to discharge this deadly little bugger! The disharge rate is tiny, but if left alone, “they hurt like hell” when bridged. I got burned by one at 250 volts, three months after the charge! OWWW! It wasnt even a “low leakage” type. Just a standard AC ...“Motor Start”... type. Beware 1 farad can kill. <p>
When I ask back said something like the voltage or capacity will change if keep for long time.
90% of this cap. are 1 farad in Thai market. <p>Sounds right? Voltage/cap will keep 90 percent for one year.

[ggroup]

So sorry the exchange rate is wrong, 43.xx/US$
not 33.
.xx!!!<p> Dear Chris Smith <p>Boy, the baht rate is up, its was only 20 baht per buck when I last visited Bangkok, back in the dark ages? How is Chang Mi these days? Still Quiet? <p>Wow mean 5-6 year ago
Chaeg mai not quiet, a lot of tourist this time?
Do you like my country?<p>Come on I invite you for dinner, OK?

[Chris Smith]

Thank you for the Invite, I would If I could, in a heart beat. I love Thai food. <p>No, I was there in 1976! <p>The Golden Triangle up there was the quietest place on earth. So much a contrast from Bangkok it was hard to believe they were both the same country? Phu-ket was before the tourist came, and stayed, and cant be the same either? <p>Nothing stays the same? <p>I hope my info helps you some what, If you need any more just ask. <p>good luck.....

[rsdandy]

might be of interest
www.allelectronics.com

[Dimbulb]

Thanks Chris Smith for clearing up the point about how these big capacitors are connected to car stereo system.<p>I found a diagram in a catalog from PartsExpress.com that shows that the positive power lead on the amplifier connects to both battery positive and capacitor positive. The negative side of the capacitor simply is grounded and thats all. <p>? I wonder is there a simple way to boost the voltage from 13.8 to 15 volts the application would be for CB radio. ?