aluminum electrolytic capacitors
TRANSCRIPT
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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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
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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