Aluminum Electrolytic Capacitors
More Bang for the Buck
Aluminum Electrolytic
Advantage
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The high value capacitor choice
Typically last more than 10 years
Lowest cost dielectric for high capacitance
and energy storage
4 to 10 times the capacitance per dollar of
film capacitors
Great for power electronics bus capacitors
to 600 V
Aluminum Electrolytic
Principal Applications
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Power-supply
input capacitors
output capacitors
Bus capacitors for inverters in
UPS systems
Motor-drives
Photoflash and Strobe Flash
Welders
Switching Power Supply
Application
Linear Power Supply
Application
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Transformer steps 120 Vrms down to 12.6 Vrms
12.6 Vrms AC voltage is 35.6 V peak to peak
Fullwave rectified voltage is 0 to 16.4 V
Add 200 µF capacitor: filtered voltage is 16 V
with ±0.4 V ripple voltage.
Ripple Current is King
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Ripple is from rectification and switching
Ripple current heats the capacitor (blue peaks below)
Higher temperature shortens capacitor life
But operating life claims and calculation methods are not
standardized, so the capacitor maker with the best models,
technology, and technical sales force has an advantage
Temperature Rise
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The temperature rise DT is the thermal
resistance q from the capacitor core to
ambient times the power P
DT = qP = qI2(ESR)
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To lower the temperature rise
lower thermal resistance q
lower power P
Lowering Temperature Rise
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Lower thermal resistance q with
Thermal Pak capacitor construction
Lower power P with lower ESR from
new electrolytes, separators & foils
You can lower q with capacitor choice
and cooling with a fan or heatsink
Thermal Pak™
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Compression Design
with extended
cathode, low
thermal resistance
Better shock and
vibration
Safety vent can’t be
blocked by tar
Lighter weight
Extended Cathode Handles
High Ripple Current
Extended
cathode foil
at right gets
heat out
Potted
Rilled
Double Peg
Compression
CDE Expected Life Calculator
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Allows you to predict life with your
operating conditions
Calculates temperature rise and
expected life for
screw terminal capacitors
snap-in capacitors
Accurate—Based on extensive thermal
measurements of capacitor materials
The following is a CDE Calculator
Comparison of 550C to DCMC
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Both in 3 inch diameter by 5⅝ long cans
550C is 3700 µF, 450 V
DCMC is 5600 µF, 450 V
Both 20 amps of ripple current at 360 Hz
Both 25 amps of ripple current at 2 kHz
Expected lives: 550C about 20 years,
DCMC about 1 year.
http://www.cde.com/calc
Screw Terminal
Capacitor Types
Type 550C, The 105 °C
Inverter Capacitor
Type 550C, The 105 °C
Inverter Capacitor
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Longest life, highest ripple current type
Standard of comparison
200 V to 450 V, inverter voltage range
Compares with UCC LXR Series
Special specifications, part number
550CExxxx
Type 520C, The 85 °C
Inverter Capacitor
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High value, high ripple current type
The next step below Type 550C
200 V to 500 V, inverter voltage range
> 80% of Type 550C ripple capability
Compares with UCC RWF Series
Rifa PEH 105 °C
Type 500C, Long-Life
Capacitor
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Twice the life of Type DCMC
6.3 V to 500 V, wide range
> 60% of Type 550C ripple capability
Compares with
CDE Type 3188
Aerovox Type CG
Rifa PEH 169 85 °C
Type DCMC, Best Value
Capacitor
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General purpose, first-choice low cost
6.3 V to 550 V, widest range
150% of Type 550C capacitance
> 40% of Type 550C ripple capability
Compares with CDE Type 3186
Aerovox Type CGS
UCC U36D Series
Typical Hi-Ripple Lifetimes
4700 µF 450 V Comparison
60 °C, 12 A @ 120 Hz, 400 V
Type
Case Size
(in)
Life
(years)
Price
(%)
DCMC
3x5⅛
4.6
100
500C
3x5⅝
9.5
110
520C
3x5⅝
23.7
130
550C
3½x5⅝
48.8
142
The Snap-in Capacitors
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Industry’s widest selection including
New Type SLPX 85°C, 3000 h, low cost
New Type SLP 105°C, 3000 h, low cost
25% smaller Types 380LQ & 381LQ
25% more ripple Type 381LR, 105°C
4 & 5 pin Types 382LX and 383LX
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http://www.cde.com/catalog/alum/#snap-in
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Type MLP, Flatpack Capacitor
Less than ½ inch tall
20 joules of energy storage
Easy to stack into modules
Easy to heatsink
Great at cold to –55 °C
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Welded seal, flat capacitor can replace
multiple snap-ins in high ripple aps
New, 450 V. Now available 7.5 to 450 V
Double the ripple capability with a heatsink
50-year life with nearly hermetic seal
MLS with stainless case, 100 year life
Next
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Remember CDE Cornell Dubilier as
your source for aluminum electrolytic
capacitors
Enjoy the benefits of the life calculator
at http://www.cde/com/calc.htm
Go to major distributors for CDE Cornell
Dubilier capacitors.