© Altronics 2002 Phone: 1300 797 007 Altronics 174 Roe St, Perth, WA 6000 Fax:
© Altronics 2002 Phone: 1300 797 007 Altronics 174 Roe St, Perth, WA 6000 Fax: 1300 789 777 ABN: 84 177 396 871 Internet: www.altronics.com.au DATASHEET CAPACITORS Polyester Capacitor Ceramic Capacitor Monolithic Capacitor A capacitor works on the principal of having two conductive plates which are very close and are parallel to each other. When a charge is applied to one plate of the capacitor, the electrons will generate an approximately equal, but opposite charge on the other plate of the capacitor. Capacitors will pass AC current, but will block DC current. A capacitor can also be used to smooth out voltage ripple, as in DC power supplies. Capacitance is measured in Farads (F). Capacitor Parameters Capacitors have five parameters. Capacitance (Farads), Tolerance (%), Maximum Working Voltage (Volts), Surge Voltage (Volts) and leakage. Because a Farad is a very large unit, most capacitors are normally measured in the ranges of pico, nano and micro farads. Working Voltage This refers to the maximum voltage that should be placed across the capacitor under normal operating conditions. Surge Voltages The maximum instantaneous voltage a capacitor can withstand. If the surge voltage is exceeded over too long a period there is a very good chance that the capacitor will be destroyed by the voltage ‘punching’ through the insulating material inside the casing of the capacitor. If a circuit has a surging characteristic, choose a capacitor with a high rated surge voltage. Leakage Refers to the amount of charge that is lost when the capacitor has a voltage across its terminals. If a capacitor has a low leakage it means that very little power is lost. Generally leakage is very small and is not normally a consideration for general purpose circuits. Tolerance As with resistors, tolerance indicates how close the capacitor is to its noted value. These are normally written on the larger capacitors and encoded on the small ones. Code Tolerance Code Tolerance C ±0.25pF D ±0.5pF E ±1pF G ±2% J ± 5% K ±10% L ±15% M ±20% N ±30% Capacitor Markings There are a two methods for marking capacitor values. One is to write the information numerically directly onto the capacitor itself. The second is to use the EIA coding system. EIA Coding The EIA code works on a very similar principle to the resistor colour code. The first two digits refer to the value with the third being the multiplier. The fourth character represents the tolerance. When the EIA code is used, the value will always be in Pico-Farads (see Decimal Multipliers ). Example 1: 103K This expands to: 1 = 1 0 = 0 3 = x 1,000 K = 10% (see Capacitor Tolerance for listings) Then we combine these numbers together: 1 0 x1,000 = 10,000pF = 0.01µF, at ±10% tolerance. Example 2. : 335K This expands to: 3 = 3; 3 = 3; 5 = x 100,000; K = ±10% Then we combine these numbers together: 3 3 x100,000 = 3,300,000pF = 3,300nF = 3.3µF, at 10% tolerance. Electrolytic Capacitor Capacitors in Series Capacitors in series can be calculated by: Note:- The new value will always be lower. Capacitors in Parallel When capacitors are placed in parallel they can be simply added together. CTotal = C1 + C2 + C3 + etc.... Note :- The new capacitance value will be higher. 1 C1 1 + C2 1 + C3 1 + etc ..... ( ) CTotal = C1 C2 C3 READING & CONVERTING CAPACITOR VALUES 1,000,000pF = 1µF = 1,000nF 100,000pF = 0.1µF = 100nF 10,000pF = 0.01µF = 10nF 1,000pF = 0.001µF = 1nF 100pF = 0.0001µF = 0.1nF 10pF = 0.00001µF = 0.01nF 1pF = 0.000001µF = 0.001nF OR ... EIA µF nF pF Code 0.001µF 1.0nF 1000pF 102 0.0012µF 1.2nF 1200pF 122 0.0015µF 1.5nF 1500pF 152 0.0018µF 1.8nF 1800pF 182 0.0022µF 2.2nF 2200pF 222 0.0027µF 2.7nF 2700pF 272 0.0033µF 3.3nF 3300pF 332 0.0039µF 3.9nF 3900pF 392 0.0047µF 4.7nF 4700pF 472 0.0056µF 5.6nF 5600pF 562 0.0068µF 6.8nF 6800pF 682 0.0082µF 8.2nF 8200pF 822 0.01µF 10nF 1.00 x104 pF 103 0.012µF 12nF 1.20 x104 pF 123 0.015µF 15nF 1.50 x104pF 153 0.018µF 18nF 1.80 x104pF 183 0.022µF 22nF 2.20 x104pF 223 0.027µF 27nF 2.70 x104pF 273 0.033µF 33nF 3.30 x104pF 333 0.039µF 39nF 3.90 x104pF 393 0.047µF 47nF 4.70 x104pF 473 0.056µF 56nF 5.60 x104pF 563 0.068µF 68nF 6.80 x104pF 683 0.082µF 82nF 8.20 x104pF 823 0.1µF 100nF 1.00 x105pF 104 0.12µF 120nF 1.20 x105pF 124 0.15µF 150nF 1.50 x105pF 154 0.18µF 180nF 1.80 x105pF 184 0.22µF 220nF 2.20 x105pF 224 0.27µF 270nF 2.70 x105pF 274 0.33µF 330nF 3.30 x105pF 334 0.39µF 390nF 3.90 x105pF 394 0.47µF 470nF 4.70 x105pF 474 0.56µF 560nF 5.60 x105pF 564 0.68µF 680nF 6.80 x105pF 684 0.82µF 820nF 8.20 x105pF 824 1µF 1000nF 1.00 x106pF 105 1.2µF 1200nF 1.20 x106pF 125 1.5µF 1500nF 1.50 x106pF 155 1.8µF 1800nF 1.80 x106pF 185 2.2µF 2200nF 2.20 x106pF 225 2.7µF 2700nF 2.70 x106pF 275 3.3µF 3300nF 3.30 x106pF 335 3.9µF 3900nF 3.90 x106pF 395 4.7µF 4700nF 4.70 x106pF 475 5.6µF 5600nF 5.60 x106pF 565 6.8µF 6800nF 6.80 x106pF 685 8.2µF 8200nF 8.20 x106pF 825 10µF 10000nF 1.00 x107pF 106 C1 C2 C3 uploads/S4/ capacitor-guide.pdf
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- Publié le Mar 07, 2021
- Catégorie Law / Droit
- Langue French
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