== Capacitors ==
== Capacitors ==
=== Basics ===
=== Basics ===
Revision as of 22:38, 19 January 2008
paxil online flip flop converter free mmf mp3 afra behn microsoft photoshop wholesale fresh roses white printers optivite .com seasame street bed bushwacker cap imported italian foods picture of angel wing tattoo kayla salary veterinarian valve ghetto cowboy festival de san remo aortic dissection polk county sheriff march of the penguins clip jameson jenna lesbian rash on buttocks allison krauss embroidery free machine pattern fast weight loss diets wood working projects tweakui burly brawl rick perry nationalgeographic.com railroad mutual funds analysis kissing anime couple dual cf tianna lynn online renters insurance quote andretti mario racing school pyrazine synthesis david banner like a pimp mobile ultrasound business freckles association mexico new realtor liveaid tummy tucks crack cocain chemical process white knight download free full pc game mazda 323 drain maintenance roof ata shipping cases burning man denzel pump up foto decapitazione americano wolfs rain stray storm bowling ball review essay leadership woman shoes cover cheap mini-skirt road runner sports foto torino austin power goldmember sell gold coins online shopko.com database service writing tenuate online keyword texas holdem buy zyban cheap carisoprodol power inverter little teen petite wake forest 13 calle lyric suave nuova gissi srl chinese pugs villa zona laghi cristina milian dip it low table top display case gestion du mariage 2.0 englewood florida condominium coupon free grocery quarterback training formal hair sonic and shadow giant manifestation drug rehab center in texas cyclops light predator 2 30th birthday party ideas door-to-door magazine sales crew comic party game epicure b movies men bulge photodiode array hp portatile pavillon tortoises for sale www jerryleelewis com online pharmacy meds used metal shelving cheap levitra absolutly free jpegs xxx live aerial picture college of the canyons flexeril online body salt scrubs sea investing in notes and mortgages hairy, pussy, thumbnails, free ugo bakhtiar rudi video tech 101 free video by eddie batista writing for government crayola color name pitchforkmedia crashing sympathetic nervous system alaskan fishing vacations babe big boob busty colombia com diazepam online ice cream makers tjmaxx playboy college girl bec cartright vampyr 500 walker una storia vera washington state government full figured woman diamond engagement gold ring yellow veterinary hospital natural vitamins rare pokemon card free female orgasm movie clips soap opera digest botox new york lin pier hotel st. petersburg florida lawn mowing simonov, konstantin luat phap thoat vong camusnagaul viewer vrml fabbrica roller team download movies free stempel fossi the used pic nsn boost i855 mobile parole office cheap phentermine air cleaner friedrich
You can think of a capacitor as sort of a rechargeable battery, connect it to a voltage and a current will flow into it charging it up, later it will have a voltage of its own that can push the current back out. The key equation for a capacitor is:
- C = capacitance ( units: farad = volts /coulomb )
- V = voltage ( unit: volts )
- Q = charge in the capacitor ( unit: coulomb )
A simple application of the formula above occurs when a constant or near constant current flow into a capacitor: then the voltage across it increases at a constant rate, the graph of the voltage against time will be a line rising ( or falling for a negative current ) from the left to the right. If the current is constant the line is straight.
Another way of thinking of a capacitor ( which is only partly correct ) is that it is a resistor with infinite resistance for DC and lower and lower resistance as the frequency goes up. This is a fair model for sinusoidal voltages and currents, but is less useful for signals such as square waves.
- ac coupling –- blocking -- isolation
- Time for a capacitor to charge or discharge is very roughly RC where R is the resistor in series with the capacitor.
- Filter ( often power supply filter )
- tuned circuits
All capacitors are formed by having 2 conductors ( or plates ) connected to the two terminals of the capacitor. The conductors are separated from each other by insulator, typically very thin. Adding charge to one side forces like charge off the opposite plate because like charges repel. The larger the plates and the closer together they are the less voltage it takes to force in the charge. If the insulator ( called the dielectric ) is too thin it will be pierced by the charge and the capacitors becomes a conductor. Typically the basic specifications for a capacitors are its capacitance and the maximum voltage that can be used without causing the dialectic to break down.
There are many diferent technologies for manufacturing capacitor each with its own advantages and disadvantages.
- Capacitor From Wikipedia, the free encyclopedia
- RC circuit From Wikipedia, the free encyclopedia
- RC Timers and Timing Circuits
- Decoupling capacitor From Wikipedia, the free encyclopedia
In electrolytic capacitors the insulating layer is formed by electro chemical action between the plates and other chemicals in the capacitor. This forms a very thin layer which allows large capacitance in a small package. Typically this works for one polarity and not another so electrolytic capacitors are marked with their polarity. There are some non-polarized electrolytics, but they are not common.
Some electrolytic capacitors manufactured between 1999 until today are made with bad electrolyte. Avoid these, see capacitor plague for more info.
"Ferrites? I don't know much about 'em, I only use ferrites in switching regulators." --National Semiconductor's Bob Pease
Can be replaced in many circumstances with an impedance inverter using only an opamp, a capacitor, and a few resistors.
List of standard 1% resistors. If you want 1% resistors, you must pick from this list or you will pay a fortune for the resistor, assuming you can ever get it.
Interpret these numbers as the "mantissa" of the value.
You can multiply the value by anything from 0.01 to about 100,000.
100 102 105 107 110 113 115 118 121 124 127 130 133 137 140 143 147 150 154 158 162 165 169 174 178 182 187 191 196
200 205 210 215 221 226 232 237 243 249 255 261 267 274 280 287 294
301 309 316 324 332 340 348 357 365 374 383 392
402 412 422 432 442 453 464 475 487 499
511 523 536 549 562 576 590
604 619 634 649 665 681 698
715 732 750 768 787
806 825 845 866 887
909 931 953 976