Resistor Terms:
'A', 'B', 'C', 'D/E', 'F-L', 'M', 'N', 'O', 'P', 'R', 'S', 'T', 'V-Z'
Panel Mount Resistor: A style of resistor that mounts to a panel, normally an adjustable resistor or potentiometer. Types of Panel Mount Resistors; graphics
Phenolic Molded Resistor: A synthetic thermosetting resins such as Bakelite, obtained by the reaction of phenols with simple aldehydes and used to make molded products, as in a resistor shell.
Photocell: A light-controlled variable resistor which has a light-to-dark resistance ratio of 1:1000.
Photoresistor: Another name for a light dependent resistor (LDR). A resistor whose resistance changes based on the light intensity.
Pi Network: A resistor network in the form of a Pi or Delta configuration. Also refer to a more detailed definition of Resistor Attenuator Networks.
Resistor Pi Network
Potentiometer: A variable resistor. Designed for frequent changes, a volume control. The output of a Potentiometer is a voltage that is variable depending upon the position of the wiper contact. The potentiometer is commonly referred to as a variable voltage divider. It, in effect, converts mechanical information into an electrical signal.Companies that Manufacturer Potentiometers.
Potentiometer
Power Rating: The maximum power the device can dissipate with out damage at some defined ambient temperature [Still-Air]. Power Ratings are provided with a continuous full-load condition. Resistor Derating must occur to allow the device to operate at higher temperatures. Maximum power dissipation normally increases as the resistor package increases in size.
Power Rating Curve
Power Rating Curve: A curve that indicates the percentage of nominal wattage to be applied at a temperature other than that specified as Maximum power dissipation. A Power Rating Curve may also be called a Derating Curve. Note the curve shown above relates to MIL-PRF-83401 [Resistor Networks]. The Power Rating for this series is given at an ambient temperature of 700C, so for temperatures below that value the device may be operated above the maximum power rating [above 100 percent].
Power Resistor: A resistor with a power dissipation higher than a quarter watt [0.25w], or half watt [0.5w]. However the military classifies power resistors as resistors having power a dissipation above 3 watts. The classification of a power resistor is subjective; a resistor having a higher power dissipation than normally used.
PTC: (Positive Temperature Coefficient) A device with a the resistance that will increase as temperature does A type of Thermistor as shown by the picture to the right. A related topic; Manufacturers of Thermistors.
Pull-up Resistor: A resistor used to pull-up or tie an unused IC input-pin to a voltage or an open-collector IC output-pin to a voltage. How to Calculate a Pull-up Resistor Value. Tri-State Outputs may also need to be pulled-up.
How to Calculate a Tri-State Pull-up Resistor Value
Pulse Duration: In some cases the power dissipation of a resistor is provided as power dissipation vs pulse duration. Normally the pulse duration curve is provided to show the peak dissipation of a resistor over 100 percent dissipation as the pulse duration is decreased.
Resistor Peak Dissipation vs Pulse Rate
