Resistors

1/4 Watt

"Fixed" .

Single Turn Trimmer

"Pot"

Multi-turn Trimmer

Potentiometer

Symbol

Potentiometer

.

Fixed

Symbol

.

Wire Wound Resistor tied as a Rheostat

Wire Wound Resistor tied as a Voltage Divider

Resistors do a lot of Useful Things! /\_TOP_/\

Voltage to Current Convertor When driving the input (base) of a transistor gain stage: you must convert the input voltage to a current by using a voltage to current convertor --a resistor. Current to Voltage Convertor When deriving a voltage from the collector of a transistor amplifier stage: you convert the output (collector) current into a voltage by using a Current to Voltage convertor in the collector circuit--you guessed it--a resistor.

/\_TOP_/\

Resistance is Determined partially by Composition, and is inversely proportional to Cross Sectional Area

Notice Also that Resistance is proportional to Length /\_TOP_/\

Resistor- Color -Code -----------------

4 Band Color Code