Which capacitor is more powerful?

[croseiv]

A 22,000 uF 71 V or a 2200 uF 200V capacitor? I don't know for certain but I suspect the latter one is due to the higher voltage rating.

Thanks for your help.

 

[3db]

A 22,000 uF 71 V or a 2200 uF 200V capacitor? I don't know for certain but I suspect the latter one is due to the higher voltage rating.

Thanks for your help.

The 1st one can only withstand 71V max before being destroyed but will hold much more charge than cap b which will withstand 200 volts. The bigger the uF value, the more energy it store.

 

[Seth=L]

What is the use? I believe the higher voltage capacitors can move energy in and out faster. I have never seen a capacitor with that high of voltage use for power supply reseviors/filtering. 71 volts is a good rating, and 22,000 uF is a very large capacitor. Small capacitors also have a faster recovery time. It is considered more ideal to have several smaller capacitors than two large ones, assuming the total capacitance is the same.

 

[croseiv]

I ask because I noticed that is the rating of the caps in my PB13-Ultra. There's one 1000 uF 200V and two 2200 uF 200 V caps. It's the first time I've ever seen a cap with a voltage rating that high.

 

[Seth=L]

I ask because I noticed that is the rating of the caps in my PB13-Ultra. There's one 1000 uF 200V and two 2200 uF 200 V caps. It's the first time I've ever seen a cap with a voltage rating that high.

Maybe it has something to do with the type of amplifier they are using. How big is the transformer?

 

[B3Nut]

If you think caps with working-voltage ratings of 200V is high, peek at a tube amp schematic. Power supply filter caps for tube amps are routinely 500WVDC or even higher. I have a bunch of 10uF and 30uF 500VDC Sprague Atoms that I'm going to be installing in the amplifiers in my Leslie organ speakers.

 

[croseiv]

Maybe it has something to do with the type of amplifier they are using. How big is the transformer?

The amp is a BASH amp. The transformer is not that big, but I can tell the amp is very powerful based on the sub's performance. It is rated at 750 watts out put.

 

[Seth=L]

The amp is a BASH amp. The transformer is not that big, but I can tell the amp is very powerful based on the sub's performance. It is rated at 750 watts out put.

Do you have a size comparison? Is it smaller than a fist, bigger than a walnut?

BASH amplifiers are more efficient, they might be a derivative of the switching amplifier.

 

[croseiv]

Do you have a size comparison? Is it smaller than a fist, bigger than a walnut?

BASH amplifiers are more efficient, they might be a derivative of the switching amplifier.

I'll guess 2" X 2"...

 

[Seth=L]

I'll guess 2" X 2"...

That's tiny. Maybe it's like those amplifiers that use power right from the wall. Sunfire does something like that. I guess they figure "it's a subwoofer, who cares if the THD is high, you can't hear it anyway".

 

[trnqk7]

Keep in mind, with ohms law, V=IR, so if you increase V, I or R must decrease accordingly. Since the subs resistance won't change, I must drop. Therefore, it would make sense that a lower voltage rated cap with a larger capacitance would hold more current (power!) than a higher voltage rated cap with less capacitance. However, the one with less capacitance would charge more quickly and also fully discharge more quickly, allowing it to be ready for the next peak in volume sooner. Like everything, it is a tradeoff. Speed vs. power-which would you rather have? And also, how much extra power is your amp going to need anyway for large surges? If it's not much, I'd rather have it charge/discharge quicker so it's ready to go more often...

 

[3db]

What is the use? I believe the higher voltage capacitors can move energy in and out faster. I have never seen a capacitor with that high of voltage use for power supply reseviors/filtering. 71 volts is a good rating, and 22,000 uF is a very large capacitor. Small capacitors also have a faster recovery time. It is considered more ideal to have several smaller capacitors than two large ones, assuming the total capacitance is the same.

Depends on the application.

 

[Halon451]

The 1st one can only withstand 71V max before being destroyed but will hold much more charge than cap b which will withstand 200 volts. The bigger the uF value, the more energy it store.

I agree with 3db on this one. the "uF" is a measurement of the capacitor's storage capacity, as expressed in farads - the electrical unit of measurement for capacitors. The 'u' in 'uF' pertains to the level of capacitance as a negative power of 10 (u = micro farad, in this case, which is very reasonable for small electronic component circuits). I capacitor with a charge of 1 F (or 1 farad) would contain an extremely high stored charge - you usually see these in large industrial components, or those big, painted caps used for competition car audio systems.

As 3db correctly stated, the voltage rating is the maximum voltage that can pass across that capacitor before it breaks down the dialectric in-between the capacitor's charge plates. Remember, a capacitor opposed a change in voltage, which makes them suitable for many applications where a regulated power supply would be needed, or a short, mid, long-term RC decay constant (such as slowly dimming lights in your car interior when you close the door, etc, etc.).

If the cap in your sub's amp is rated for 200V, my hunch is that it is in someway attached to your incoming power supply (120V), and is probably used for regulating purposes, to achieve a more constant voltage to the step down transformers. I'm just hazarding a guess though, as I don't have anything to really go on, it's hard to visualize what you've got there.

 

[TLS Guy]

A 22,000 uF 71 V or a 2200 uF 200V capacitor? I don't know for certain but I suspect the latter one is due to the higher voltage rating.

Thanks for your help.

Physics again!

The capacitance in Farads = the charge in Coulombs/ the voltage.

So the charge in Coulombs = the capacitance x the voltage.

Lets take a look.

0.022F x 71V = 1.562 Coulombs

0.0022F X 200V = 0.44 Coulombs.

So the 22,000uF takes the prize.

Now you can not exceed the voltage rating of a cap and that means peak voltage not RMS. In fact if you don't want trouble you leave a little margin.

 

[TLS Guy]

Keep in mind, with ohms law, V=IR, so if you increase V, I or R must decrease accordingly. Since the subs resistance won't change, I must drop. Therefore, it would make sense that a lower voltage rated cap with a larger capacitance would hold more current (power!) than a higher voltage rated cap with less capacitance. However, the one with less capacitance would charge more quickly and also fully discharge more quickly, allowing it to be ready for the next peak in volume sooner. Like everything, it is a tradeoff. Speed vs. power-which would you rather have? And also, how much extra power is your amp going to need anyway for large surges? If it's not much, I'd rather have it charge/discharge quicker so it's ready to go more often...

Charge is measured in Coulombs.

 

[trnqk7]

which can be related to current or voltage or power or anything else you want it to be. I was using terms that all were familiar with. And I never said that charge=current explicitly.

 

[3db]

which can be related to current or voltage or power or anything else you want it to be. I was using terms that all were familiar with. And I never said that charge=current explicitly.

current is coulombs per sec ..unit of measure being amperes. Here's a wiki. I'm not good with words;

http://en.wikipedia.org/wiki/Ampere

 

[trnqk7]

point still being, that what I said is not inaccurate-since current is defined by coulombs, saying that a capacitor holds more current is not inaccurate and is more likely to be understood by those who don't hold EE degrees.

 

[TLS Guy]

which can be related to current or voltage or power or anything else you want it to be. I was using terms that all were familiar with. And I never said that charge=current explicitly.

This is the sort of woolly thinking that causes endless confusion. Current is a vector. It has to flow and has a direction. A charge is static. Just like the charge in a battery, until you draw current, the the charge falls.

 

[NickN]

point still being, that what I said is not inaccurate-since current is defined by coulombs, saying that a capacitor holds more current is not inaccurate and is more likely to be understood by those who don't hold EE degrees.

+1, simple explanations are not always the most accurate but they often make more since to people that are not familiar with the subject.