What is the difference between a standard capacitor and a coupling capacitor?

Answer 1

Coupling capacitors are used to couple different stages so as to prevent DC from the o/p of one stage to go into the i/p of the next stage. For instance in coupling two BJT (bipolar junction transistors) it is required to use coupling capacitor to allow only ac signal from the o/p of fisrt stage to go to i/p of next BJT as incoming dc can distrub the biasing of the other BJT.

Bypass capacitors are used to bypass the ac signal to ground. A capacitor is connected b/w the gnd and the wire. For ac signal capacitor will behave as short and will bypass it. However dc will not be bypassed as capacitor will behave as open for DC.

Answer 2

hi, the answer could propably be "the bypass capacitors are used with (slow varying) signals in order to filter out the high frequency noise where as the decoupling capacitors are used to filter out noise in power line, for example each ic in a circuit could be working at different frequencies and drawing different powers, these would cause variation in VCC ( at high frequencies) as the power traces also have resistances. Decoupling capacitors reduce the effect experienced by the neighbouring ICs. In contrast the bypass capacitor is used with signals and decoupling capacitor is associated with power supply.

Answer 3

There is no difference. A capacitor is a capacitor. The difference is just in the value, polarity (if there is any), and use.