Aluminum Electrolytic Capacitors

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Aluminum Electrolytic Advantage

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

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Aluminum Electrolytic Principal Applications Power-supply

input capacitors output capacitors

Bus capacitors for inverters in UPS systems Motor-drives

Photoflash and Strobe Flash Welders

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Switching Power Supply Application

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Linear Power Supply Application

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.

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Ripple Current is King 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

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Temperature Rise The temperature rise DT is the

thermal resistance q from the capacitor core to ambient times the power P DT = qP = qI2(ESR)

To lower the temperature rise lower thermal resistance q lower power P www.ppttopics.com

Lowering Temperature Rise 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

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Thermal Pak™ Compression Design with extended

cathode, low thermal resistance Better shock and vibration Safety vent can’t be blocked by tar Lighter weight

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Extended Cathode Handles High Ripple Current

Extended cathode foil at right gets heat out

Rilled

Potted

Double Peg Compression

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CDE Expected Life Calculator 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

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The following is a CDE Calculator Comparison of 550C to DCMC

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.www.ppttopics.com

http://www.cde.com/calc

Screw Terminal Capacitor Types

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Type 550C, The 105 °C Inverter Capacitor

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Type 550C, The 105 °C Inverter Capacitor 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

550CExxxxwww.ppttopics.com

Type 520C, The 85 °C Inverter Capacitor 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 °Cwww.ppttopics.com

Type 500C, Long-Life Capacitor 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

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Type DCMC, Best Value Capacitor 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 Serieswww.ppttopics.com

Typical Hi-Ripple Lifetimes 4700 µF 450 V Comparison 60 °C, 12 A @ 120 Hz, 400 V

Type Case Size Life Price   (in) (years) (%)

DCMC 3x5⅛ 4.6 100

500C 3x5⅝ 9.5 110

520C 3x5⅝ 23.7 130

550C 3½x5⅝ 48.8 142

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The Snap-in Capacitors 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 http://www.cde.com/catalog/alum/

#snap-in

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Type MLP, Flatpack Capacitor

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

Less than ½ inch tall20 joules of energy storageEasy to stack into modulesEasy to heatsink Great at cold to –55 °C

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Next 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.

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