The problem is: how *THIN* is 5V or 50V of Teflon? Incredibly thin. Too thin to handle. Too thin to make without defects.
There is a minimum-COST thickness for plastic film. Thicker costs more for the plastic. Thinner costs more for the care in manufacturing and handling.
Bulk Teflon is good for 60MV (MegaVolts) per meter. Working that out in furlongs, a 6V film would be 0.000,004 inches.
Here's a source for Teflon film. A 25' roll of 0.0005"Teflon® FEP Film x 24" is not real expensive. By my figuring, 0.0005 is good for 760 Volts, would perhaps be sold as 200V in a cap. Thinner film is not readily available--- oh, here's 0.000,4" stuff and 0.000,2" (GF40964058) (expensive!).
Due to the voltage swings and transients in music, it is preferable according to someone I trust that capacitor voltage in speakers should not be rated below 100V, and that due to +/- AC voltage swings in music, that 250V are really closer to ideal.
You have to realize that arcing can occur in a capacitor that is not rated at a high enough voltage when frequency cycles increase, such as in tweeters. I heard this from a capacitor engineer at Plastic Capacitors, which is a sister company to Arizona Caps, and a manufacturer of high voltage products.
If I could find the article my source attached when I read this before, I would link it here. He is knowledgeable, employed by and has consulted for, many audio companies; as well as builds his own amplifiers.
One last bit of info- you need to size capacitors under use generally at the 4x rating required in terms of voltage. This also ensures reliability.
I would not use a 5VAC cap in a speaker- ever. 100V minimum, 250V ideal, and higher is better internal contact and lower ESR.
Later,
Wolf
You have to realize that arcing can occur in a capacitor that is not rated at a high enough voltage when frequency cycles increase, such as in tweeters. I heard this from a capacitor engineer at Plastic Capacitors, which is a sister company to Arizona Caps, and a manufacturer of high voltage products.
If I could find the article my source attached when I read this before, I would link it here. He is knowledgeable, employed by and has consulted for, many audio companies; as well as builds his own amplifiers.
One last bit of info- you need to size capacitors under use generally at the 4x rating required in terms of voltage. This also ensures reliability.
I would not use a 5VAC cap in a speaker- ever. 100V minimum, 250V ideal, and higher is better internal contact and lower ESR.
Later,
Wolf
I just got some WIMA MKP 1uF for $1 each and ASC polypropylenes 20uF for $2 each from Allelectronics:
Polypropylene | All Electronics Corp.
Polypropylene | All Electronics Corp.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.