#include: A preprocessor directive that causes the named file to be inserted in place of the #include.

Zener Voltage: The breakdown voltage of a zener diode. This is the approximate voltage out of a zener voltage regulator.

Zener Resistance: The bulk resistance of a zener diode. It is very small compared to the current-limiting resistance in series with the zener diode.

Zener Effect: Sometimes called high-field emission, this occurs when the intensity of the electric field becomes high enough to dislodge valence electrons in a reverse-biased diode.

Zener Diode: A diode designed to operate in reverse breakover with a very stable voltage drop.

Wien-bridge oscillator: An RC oscillator consisting of an amplifier and a Wien bridge. This is the most widely used low-frequency oscillator. It is ideal for generating frequencies from 5 Hz to 1 MHz.

Wafer: A thin slice of a crystal used as a chassis for integrated components.

Voltage-to-Current Converter: A circuit that is equivalent to a controlled current source. The input voltage controls the current. The current is then constant and independent of the load resistance.

Voltage Source: Ideally, an energy source that produces a constant load voltage for any value of the load resistance. To a second approximation, it includes a small internal resistance in series with the source.

Voltage Regulator: A device or circuit that holds the load voltage almost constant, even though the load current and source voltage are changing. Ideally, a voltage regulator is a stiff voltage source with an output or Thevenin resistance that approaches zero.

Voltage Multiplier: Direct current power-supply circuit used to provide transformerless step-up of ac line voltage.

Voltage Gain: This is defined as the output voltage divided by the input voltage. Its value indicates how much the signal is amplified.

Voltage Follower: An op-amp circuit that uses noninverting voltage feedback. The circuit has a very high input impedance, a very low output impedance, and a voltage gain of 1. It is ideal for use as a buffer amplifier.

Voltage Feedback: This is a type of feedback where the feedback signal is proportional to the output voltage.

Voltage-Divider Bias (VDB): A biasing circuit in which the base circuit contains a voltage divider that appears stiff to the input resistance of the base.