من همیشه فکر می کردم که خازن های 105 درجه الکترولیتی از خازن های 85 درجه الکترولیتی در شرایط مساوی بهتر هستن و حداقل طول عمر بیشتری دارن. امروز داشتم یک مقاله می خوندم دو نفر چیز های جابی در این مورد گفته بودن. خوندنش خالی از لطف نیست. در ضمن به آدرس های ایمیل هم توجه بکنین! :?
(From: Jeroen H. Stessen (Jeroen.Stessen@philips.com).)
Electrolytic capacitors like to be kept cool! If there's anything that these capacitors can't stand, it's heat. It causes
them to dry out.
Electrolytic capacitors exist in (at least) two different temperature ratings: 85 C and 105 C. The latter are
obviously more temperature resistant. Unfortunately they also tend to have a higher ESR than their 85 C
counterparts. So in an application where the heat is due to I^2 * ESR dissipation, the 105 C type may actually be a
*worse* choice! If the heat is due to a nearby hot heatsink then 105 C is indeed a better choice.
اینهم نظر آقای دیگه :roll:
ESR is usually something to be minimized in a capacitor. However, where the original design depended (probably
by accident) on a certain ESR, this may not always be the case:
(From: Lee Dunbar (dunbar@unitrode.com).)
Substitutions of low ESR caps into circuits which had lousy caps is not always the good idea that it appears to
be.... Caution is advised, as low ESR caps will not limit surge currents.
The circuits' series impedance drops (compare substituted capacitors ESR when new with the original capacitor's
ESR was when it was a new capacitor), which, in turn, lets the surge magnitude rise, the higher currents destroy
can semiconductors and other components.
I guess what the industry needs is a good capacitor cross reference guide for aluminum electrolytics!
شهریار :roll:
(From: Jeroen H. Stessen (Jeroen.Stessen@philips.com).)
Electrolytic capacitors like to be kept cool! If there's anything that these capacitors can't stand, it's heat. It causes
them to dry out.
Electrolytic capacitors exist in (at least) two different temperature ratings: 85 C and 105 C. The latter are
obviously more temperature resistant. Unfortunately they also tend to have a higher ESR than their 85 C
counterparts. So in an application where the heat is due to I^2 * ESR dissipation, the 105 C type may actually be a
*worse* choice! If the heat is due to a nearby hot heatsink then 105 C is indeed a better choice.
اینهم نظر آقای دیگه :roll:
ESR is usually something to be minimized in a capacitor. However, where the original design depended (probably
by accident) on a certain ESR, this may not always be the case:
(From: Lee Dunbar (dunbar@unitrode.com).)
Substitutions of low ESR caps into circuits which had lousy caps is not always the good idea that it appears to
be.... Caution is advised, as low ESR caps will not limit surge currents.
The circuits' series impedance drops (compare substituted capacitors ESR when new with the original capacitor's
ESR was when it was a new capacitor), which, in turn, lets the surge magnitude rise, the higher currents destroy
can semiconductors and other components.
I guess what the industry needs is a good capacitor cross reference guide for aluminum electrolytics!
شهریار :roll:
