What is a Stage? Explain its functioning. - Electronics
Explain what do you understand by a Stage? Explain its functioning.
- A Stage is a set of components with a capacitor at the input and a capacitor on the output. A capacitor only has an effect on the circuit during the time when it gets charged or discharged. When a capacitor is placed between two stages, it gradually charges. When it is charged, the voltage on one stage does not affect the voltage on the next stage. That's why the capacitor is drawn as two lines with a gap.
- A capacitor is like putting a magnet on one side of the door and a metal sheet on the other. Moving the magnet up and down will move the metal up and down but the two items never touch. Only a rising and falling voltage is able to pass through the capacitor has a capacitor on the input and output. This means the stage is separated from anything before it and anything after it as far as the DC voltages are concerned and the transistor will produce its own operating point via the base resistor and LOAD resistor. The value of the two resistors should be chosen so the voltage on the collector should be half-rail voltage and this is called the "idle" or "standing" or "quiescent" conditions. It is the condition when no signal is being processed.
- When the voltage on the collector is mid-rail, the transistor can be turned off a small amount and turned on a small amount and the voltage on the collector will fall and rise. (note the FALL and RISE).