size of electrolytic caps

ebp

Joined Feb 8, 2018
2,332
Do you mean different capacitance or voltage or just smaller physical size? Capacitors have been shrinking in physical size over the years, and it is now possible to get caps with excellent specs that are smaller than very ordinary caps used to be.

What are you replacing? (photo?). What do you plan to use as a replacement? (part number?, data?)
 

Thread Starter

andomando

Joined Jan 23, 2016
10
Do you mean different capacitance or voltage or just smaller physical size? Capacitors have been shrinking in physical size over the years, and it is now possible to get caps with excellent specs that are smaller than very ordinary caps used to be.

What are you replacing? (photo?). What do you plan to use as a replacement? (part number?, data?)
I am replacing my guitar amplifier filter capacitors.4700uf 50v.
 

DickCappels

Joined Aug 21, 2008
7,978
Size might relate to equivalent series resistance (ESR) or ripple current rating. A high ESR could affect the quality of the amplifier's output depending upon the particular circuit and where in the circuit the capacitor is located. For a given ripple current at a particular frequency the lower the ripple current rating of the capacitor the shorter the capacitor's life.

If possible find the ripple current rating of the original part then get a replacement part with the same or higher ripple current rating.
 

Thread Starter

andomando

Joined Jan 23, 2016
10
Size might relate to equivalent series resistance (ESR) or ripple current rating. A high ESR could affect the quality of the amplifier's output depending upon the particular circuit and where in the circuit the capacitor is located. For a given ripple current at a particular frequency the lower the ripple current rating of the capacitor the shorter the capacitor's life.

If possible find the ripple current rating of the original part then get a replacement part with the same or higher ripple current rating.
Thank you for your help.
kind regards
Andrew
 

dl324

Joined Mar 30, 2015
13,520
I am replacing my guitar amplifier filter capacitors.4700uf 50v.
Does smaller size refer to the physical dimensions or the capacitor value? Either could cause problems.

Smaller physical dimensions at the same voltage rating may not be as robust as the larger physical dimension (which can provide greater plate separation).

A smaller value could also cause problems, but we can't say with any certainty without knowing how the capacitor was being used.
 

Thread Starter

andomando

Joined Jan 23, 2016
10
Does smaller size refer to the physical dimensions or the capacitor value? Either could cause problems.

Smaller physical dimensions at the same voltage rating may not be as robust as the larger physical dimension (which can provide greater plate separation).

A smaller value could also cause problems, but we can't say with any certainty without knowing how the capacitor was being used.
The capacitors are filter caps in my guitar amplifier, the old caps size;( 50mm x 35mm,,2"x1.3/8")
new ones;(1.1/4"x1.3/8") i also have some at(;1.3/8"x3/4" ) all the same values.
regards for your help
Andrew
 

dl324

Joined Mar 30, 2015
13,520
The capacitors are filter caps in my guitar amplifier, the old caps size;( 50mm x 35mm,,2"x1.3/8")
new ones;(1.1/4"x1.3/8") i also have some at(;1.3/8"x3/4" ) all the same values.
Are the voltage and temperature ratings also the same?

If the voltage ratings are the same, the smaller caps might be less reliable; it depends on how much they were derated in the original design.
 

Thread Starter

andomando

Joined Jan 23, 2016
10
Are the voltage and temperature ratings also the same?

If the voltage ratings are the same, the smaller caps might be less reliable; it depends on how much they were derated in the original design.
Info on original caps ;(ITT. RED POS 4700 UF, 50 VD./C,,,31104 102,,,,,7824) don,t see temp on these ?? could it be the 102 ?
Info on other caps; 4700 uf,,50v,,,vent -40+105 degrees C. size;1.3/8" x 3/4"
4700 uf 100v....ieff.(20 KHz) 10,8A (70 deg C.,,2222 114 19472 HP. SIZE;3 1/8TH X 2".
I also have others.
regards
Andrew
 
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