======================COMPONENTS_CAPACITORS================================ capacitor material Aluminium Electrolytics: 1. Cheap per farad 2. Small per farad 3. Drifty 4. Limited life (they dry out, especially if hot) 5. Leaky 6. Poor at mid and high freq. 7. Tolerance: poor 8. temperature range: restricted Electrolyte dielectric is a thin layer of aluminum oxide. electrolyte is usually boric acid or sodium borate in aqueous solution together with various sugars or ethylene glycol to retard evaporation. 2->20mOhms 22->6800uF +/-20% _ _ _ ___ / \/ \/ \ ___ | |_/\ /\ /\_______||________________| () () |_| | |___| \/ \/ | || | |___| | | 65mA->2.5A |_/\ /\ /\_| Max_rms ripple \/ \/ ---------------------------------------------------------------------------- Tantalum Electrolytics 1. Cheap, but not as cheap as Alum 2. Small, but not as small as alum 3. Drifty, but better than alum 4. Better life than Alum 5. Less leaky than alum 6. Good up to high audio freqs. 7. Tolerance: better than alum 8. temperature range: better than alum, Tantalum cathode electrode is formed of sintered tantalum grains, with the dielectric electrochemically formed as a thin layer of oxide. thin layer of oxide and high surface area of the porous sintered material cathode electrode is formed either of a liquid electrolyte connecting the outer can or a chemically deposited layer of manganese dioxide, connected to wire lead. 4->1 Ohms 30->850 uF +/-20% _ _ _ ___ / \/ \/ \ ___ | |_/\ /\ /\_______||________________| () () |_| | |___| \/ \/ | || | |___| | | Tant 820mA->2.5A |_/\ /\ /\_| Max_rms ripple \/ \/ Ileakage_uAs 2uA->16uA ---------------------------------------------------------------------------- PolyEster (mylar) 3. much less drifty than electrolytics 4. much longer life 5. very low leakage 6. usable up to RF 7. Fairly tight tolerence available 8. temperature range: good at low temps,can melt 4->1 Ohms 2n->100 uF +/-2 % _ _ _ ___ / \/ \/ \ ___ | |_/\ /\ /\_______||________________| () () |_| | |___| \/ \/ | || | |___| | | Polyester9-18nH |_/\ /\ /\_| \/ \/ DF 10-4 ---------------------------------------------------------------------------- 5m->30mOhms 1n->4.7 uF +/-2 % _ _ _ ___ / \/ \/ \ ___ | |_/\ /\ /\_______||________________| () () |_| | |___| \/ \/ | || | |___| | | Polyprop 12nh Max Pulse |_/\ /\ /\_| 200->2800V/us \/ \/ DF tan(d) .4e-3 ---------------------------------------------------------------------------- 5m->30mOhms 1p->2600pF +/-.5% _ _ _ ___ / \/ \/ \ ___ | |_/\ /\ /\_______||________________| () () |_| | |___| \/ \/ | || | |___| | | Mica 12nh Max Pulse |_/\ /\ /\_| 200->2800V/us \/ \/ DF tan(d) 0.1% ---------------------------------------------------------------------------- Ceraminc. Low 1. Cost: high per farad 2. Size large per farad 3. Drift: among best 4. Life: long 5. Leakage: very low 6. Usable freqs: RF 7. Tolerence: very tight 8. temperature range: wide 9. Voltage: very high available Medium 3. Drift: better than electrolytic, worse than polyester 4. Life: long 5. Leakage: low 6. Usable freqs: RF 7. Tolerence: moderate 8. temperature range: wide High 3. Drift: very 4. Life: long 5. Leakage: low probably (not sure) 6. Usable freqs: low RF 7. Tolerence: medium to poor 8. temperature range:restricted high and low ---------------------------------------------------------------------------- Aluminium Electrolyt Cheap/Small/Leaky/Drifty/Limited life,dry outhot Poor mid ->high freq, seen in power supplies. Tantalum Electrolyt Cheap/Small/Drifty/Less leaky/Better life/ Good up to high audio freqs. Tolerance: better PolyEster (mylar) much less drifty/much longer life/very low leakage usable to RF,Fairly tight tolerence ,can melt Ceraminc Low best Drift/very lowLeakage /very tightTolerence temperature/voltage range wide, long life For RF,High cost Ceraminc Medium Tolerence moderate, Drift worse than polyester Ceraminc High very Drift: low RF Tolerence: medium to poor Metialize film caps advantage at self heating and size deposit metal in liqified state to dielectric surface mylar inexpensive but temp dependent polycarbinate low freq dependence . low temp effect electroylics caps +75% -10% 80% -55C 112% at 125C electroylics imped 300(R*C) 0dB at 300c and 20dB at -55C electroylics leak 5uA -> 30uA at 125C ---------------------------------------------------------------------------- Ceramic caps up to 100MHz Micra up to 200MHZ polystryrene up to 200MHZ ---------------------------------------------------------------------------- mylar inductance Q Energy_stored/energy_loss Rp/sqrt(L/C) RS*RP=L/C Q number of cycles to settle silver mica max 0.1uF stable ,expensivve ceraminc up to 1000MHz ---------------------------------------------------------------------------- CAPACITOR 10|..C............................ | C . . . L . | . . L . | C . L . . | C. . L . . | C . L . . 1|.........C......L.............. | . C .L . . | . C L . . | . C L . . . | . R . . . | . . . . .1|............................... | . . . | IMPEDANCE OF 0.1uF . | . . . . | . . . . | . . . . |_____________________________ . 100KHz 1MHz 10MHz 100MHz 1GHz ======================D_F_capacitor=========================== D_F_capacitor? DF = dissipation factor (%) = Tan d = ESR / Xc Xc = 1 / (2pi f C) Power Factor (%) = ESR / total impedance = sin (loss angle) = cos (phase angle) Q = quality factor = cotan (loss angle) = 1 / DF Power loss = 2pi f C V² DF = I² ESR ======================ESL_for_Capacitors====================================== ESL_for_Capacitors Residual inductance (ESL) Type of Capacitor Leaded disc ceramic capacitor 3.0 nH(0.01 mF) Leaded disc ceramic capacitor 2.6 nH(0.1 mF) Leaded monolithic ceramic capacitor 1.6 nH(0.01 mF) Leaded monolithic ceramic capacitor 1.9 nH(0.1 mF) Chip monolithic ceramic capacitor 0.7 nH(0.01 mF, Size: 2.0 x 1.25 x 0.6 mm) Chip monolithic ceramic capacitor 0.9 nH(0.1 mF, Size: 2.0 x 1.25 x 0.85 mm) Chip aluminum electrolytic capacitor 6.8 nH(47 mF, Size: 8.4 x 8.3 x 6.3 mm) Chip tantalum electrolytic capacitor 3.4 nH(47 mF, Size: 5.8 x 4.6 x 3.2 mm) ======================making_capacitors====================================== Energy stored in capacaitor E = (1/2)*Q*V better term E = (1/2)*(V^2)*C or (1/2)*(Q^2)/C ___ | 1V| |___| A 1 farad would be able to store 1 Coul of charge 1F | _|_ +++ with only 1 volt across it. ___ --- ________________________________ | 1C | Capacitor_definition C = Q/V | _|_ | 1Farad = 1Coul/Volt | /// |________________________________| making_capacitors C = .0885 er*A*(N-1)/t C = capacitance in pF er is dielectric constant relative to air A = plate area in sq cm t = thickness in centimeters Assuming t = .0625" = 0.1588cm A = 34" x 46" = 1E4 cm^2 er = 4 then to get C = 0.5E12 pF -- you need a pretty big N. In fact, it looks like the thing would take up quite--- size_uF freq_MHz Rmin Polyester caps 1.0 2 .02 Polyester caps 0.01 20 .1 ceramic dip caps 1.0 2 .03 ceramic dip caps 0.01 20 .2 tantalium 47.0 .1->3 .2 tantalium 4.7 10 2 ---------------------------------------------------------------------------- Electrolyte CAP Electrolyte _ Alum Oxide Dielectric soaked paper | | V V _ _ || | | | || _____|| | | | ||_____ |_____ | | | | | _____| cathode || | | | || Anode foil || |_| |_|| 1) etch foil 2) grow oxide with voltage applied 3) thickness =0.06E-6 in/V_applied _ _ _ /*\/ \/ \ ___ ESR | () () | ___ wound core 150uF | |_/\ _____||__| 100uH |_| | resonate 10KHz 100KHz |___| \/ | || | |___| | | |_/\ __| \/ DCL ESR equiv_serie_r decreases with temp .1 to 10ohms DCL direct_Current_Leakage a function of temp voltage (if reverse V high current,decrease Cap ,higher DCL) max temp 65C to 85C up 30% cap -30C =-60% cap with increase in ESR age cap cap drop with age 75->73 DF dissiaption factor =(2*PI*F*C)*(ESR)/1E4 PF power factor =ESR/Z Ileak_max (50nA/(uF*V))*(rated_C)*(rated_V) for C<1000uF*1V about 5uA (30nA/(uF*V))*(rated_C)*(rated_V) +20uA for C*V <1000uF ---------------------------------------------------------------------------- D.F. in capacitor DF = dissipation factor (%) = Tan d = ESR / Xc Xc = 1 / (2pi f C) Power Factor (%) = ESR / total impedance = sin (loss angle) = cos (phase angle) Q = quality factor = cotan (loss angle) = 1 / DF Power loss = 2pi f C V² DF = I² ESR ---------------------------------------------------------------------------- dielectricabsorption takes work to align the atoms of dielectric when imposed by a voltage. While in Army, newbie was discharging input filter caps to a shed supplied with AC from a substation thinking it was a safe way to handle caps quickly. He did this with a screwdriver. An automotive mechanics screwdriver - a biggie. Not only did he vaporized the screwdriver, he suffered severe injuries to include burns from flying molten metal. He also suffered partial blindness because the arcing caused such severe ultraviolet radiation, it partially burned part of his retina. Several hundred times the arc of a normal electric welding torch. ======================Capacitor_Codes======================================== read Capacitor_Codes Large capacitor have value on them, such as 10.uF most three numbers, sometimes just two read as Pico-Farads. 47 printed on a small disk can be assumed to be 47 Pico-Farads three numbers first two are the 1st and 2nd significant digits third is a multiplier code. Table 1 Digit multipliers Third digit Multiplier (this times the first two digits gives you the value in Pico-Farads) 0 1 1 10 2 100 3 1,000 4 10,000 5 100,000 6 not used 7 not used 8 .01 9 .1 A capacitor marked 104 is is 100,000pF So a 103J is a 10,000 pF with +/-5% tolerance Table 2 Letter tolerance code Letter symbol Tolerance of capacitor B +/- 0.10% C +/- 0.25% D +/- 0.5% E +/- 0.5% F +/- 1% G +/- 2% H +/- 3% J +/- 5% K +/- 10% M +/- 20% N +/- 0.05% P +100% ,-0% Z +80%, -20% Now to be really complicate things there is sometimes a letter-number-letter (like Z5U) code that gives information. Table 3 shows how to read these cryptic codes. A 224 Z5U would be a 220,000 pF (or .22 uF) cap with a low temperature rating of -10 deg C a high temperature rating of +85 Deg C and a tolerance of +22%,-56%. Table 3 Dielectric codes First Second Third MAX. symbol Low symbol High Symbol Capacitance (a temperature (a Temperature (a change over letter) requirement number) requirement letter) temperature Z +10 deg. C 2 +45 deg. C A +1.0% Y -30 deg. C 4 +65 deg. C B +/- 1.5% X -55 deg. C 5 +85 deg. C C +/- 2.2% 6 +105 deg. C D +/- 3.3% 7 +125 deg. C E +/- 4.7% F +/- 7.5% P +/- 10.0% R +/- 15.0% S +/- 22.0% T +22%, -33% U +22%, -56% V +22%, -82% There are some Capacitor color codes - the last dot is the tolerance code where brown is +/-1% red +/-2% as in the resistor color code with two exceptions black is +/- 20% and white is +/- 10% going backward the three dots to the left of the tolerance dot form the value in pF There will be two or three more color dots before the value but they mean different things about temperature range and coefficient depend which one of three systems is used - so I will leave it out for now unless some one asks. There are two more number systems seen on caps. The first one can be recognized as the EIA because it starts with an R. R DM 15 F 471(R) J 5 O (C) The above number means the following R tells us this is an EIA code DM is a dipped case style CM would be a molded case style 15 is the case size code - if anyone asks I will put up a table for this F is the characteristic code from table 4 the R is a decimal point when used (not often) the 471R first two digits form the significant value and the third is the multiplier thus, this is a 470pF part J is the capacitance tolerance code as given in table 2 above thus J is a 5% part 5 is the DC working voltage in hundreds of volts (EIA only) thus 500V O is the temperature range from table 5 C tells us the leads are crimped where a S would tell us they are straight. This next one is the Military code CM 15 B D 332 K N 3 CM is the case code - DM is a dipped case style CM would be a molded case style 15 is the case size code - if anyone asks I will put up a table for this B characteristic code tells us it doesn't have a drift specified (from table 4) D is tHe Military voltage code from table 6 332 tells us that it is 3,300pF K tells us from table 2 that this is a 10% part N gives us our temperature range of -55 to 85 °C from table 5 3 The 3gives the vibration grade 3 tells us 20g at 10 to 2,000 hz for 12 hours (1 is 10G at 10 to 55 Hz for 4.5 hours) Table 4 characteristic codes EIA or MIL characteristic Maximum capacitance Maximum range of Temp code drift coefficient B Not specified Not specified C +/-(0.5% + 0.1pF) +/- 200 ppm/°C D +/-(0.3% + 0.1pF) +/- 100 ppm/°C E +/-(0.1% + 0.1pF) -20 to +100 ppm/°C F +/-(0.05% + 0.1pF) 0 to +70 ppm/°C Table 5 Temperature range M -55 to 70 °C N -55 to 85 °C O -55 to 125 °C P -55 to 150 °C Table 6 Mil voltage range code in volts A 100 B 250 C 300 D 500 E 600 F 1,000 G 1,200 H 1,500 J 2,000 K 2,500 L 3,000 M 4,000 N 5,000 P 6,000 Q 8,000 R 10,000 S 12,000 T 15,000 U 20,000 V 25,000 W 30,000 X 35,000 Now that you know more than most EE's about reading capacitor codes why not take a look at our Capacitor Wizard