first let us discuss the working of a capacitor.
INSIDE THE CAPACITOR
KINDS OF CAPACITORS
Reading Capacitor Labels
Reading capacitor labels is tricky business. Each family of capacitors uses its own unique labeling system. Some systems are easy to understand, whereas others make use of misleading letters and symbols. The best way to figure out what a capacitor label means is to first figure out what family the capacitor belongs to. After that, try seeing if the capacitor label follows one of the conventions in the below figure
Important Things to Know about CapacitorsEven though two capacitors may have the same capacitance values, they may have different voltage ratings. If a smaller-voltage capacitor is substituted in place of a higher-voltage capacitor, the voltage level across the replacement may “zap” its dielectric, turning it into a low-level resistor. Also remember that with polarized
capacitors, the positive lead must go to the more positive connection; otherwise, it may get zapped as well.
As a practical note, capacitor tolerances can be atrocious. For example, an aluminum electrolytic capacitor’s capacitance may be as much as 20 to 100 percent off the actual value. If an application specifies a low-tolerance capacitor, it is usually safe to substitute a near-value capacitor in place of the specified one.