base		A square wave of fixed frequency but variable duty cycle.
diode		Allows current to flow only in one direction untill voltage reaches a specific point. then voltage and current can flow in a reverse direction.
semiconductor		Diodes that turn on or off when subjected to light.
transistors		Made of exactly 4 electrons in it's outer ring
duty cycle		Acts like a relay but has no moving parts.
zener diode		A variable resistor that reacts to temperature.
power rectifier diode		A diode that produces light when forward biased.
photo diode		Used in an Voltage generator to convert A/C into D/C.
doping		Number of pulses per second.
analog		The control part of the transistor.
thermistors		Voltage operates on a variable voltage value.
light emitting diode		The point wherea P
pulse width modulation		Small amounts of impurities added to a semiconductor.
PN junction		A one way check valve for electricity
emitter		The part of the transistor that has an arrow on it.