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P1

paper capacitor
Fixed capacitor using oiled or waxed paper as a dialectric.

parallel
Circuit having two or more paths for current flow. Also called shunt.

parallel resonant circuit
Circuit having an inductor and a capacitor in parallel with one another. Circuit offers a high impedance at resonant frequency. Sometimes called a "tank circuit."

pass band
The range of frequencies that will be passed and amplified by a tuned amplifier. Also the range of frequencies passed by a band pass filter.

passive component
Component that does not amplify a signal. Resistors and capacitors are examples.

pasive filter
A filter that contains only passive or non amplifying components.

passive system
System that emits no energy. It only receives. It does not transmit or reveal its position.

peak
Maximum or highest amplitude level.

peak inverse voltage
(PIV) The maximum rated value of a AC voltage acting in the direction opposite to that in which a device is designed to pass current.

peak to peak
Difference between the maximum positive and maximum negative values of an AC waveform.

pentavalent element
Element whose atoms have five valence electrons. Used in doping intrinsic silicon or germanium to produce n-type semiconductor material. Most commonly used pentavalent materials are arsenic and phosphorus.

percent of regulation
The change in output voltage that occurs between no-load and full-load in a DC voltage source. Dividing this change by the full-load value and multiplying the result by 100 gives percent regulation.

percent of ripple
The ratio of the effective rms value of ripple voltage to the average value of the total voltage. Expressed as a percentage.

period
Time to complete one full cycle of a periodic or repeating waveform.

permanence
Magnetic equivalent of magnetic inductance and consequently equal to the reciprocal of reluctance, just as conductance is equal to the reciprocal of resistance.

permanent magnet
Magnet normally made of hardened steel that retains its magnetism indefinately.

permeability
Measure of how m how much better a material is as a path for magnetic lines of force with respect to air which has a permeability of one. Symbolized by the Greek lower case letter mu (m).

phase
Angular relationship between two waves.

phase angle
Phase difference between two or more waves, normally expressed in degrees.

phase shift
Change in phase of a wave form between two points, expressed as degrees of lead or lag.

phase shift oscillator
An oscilator that uses three RC networks in its feedback path to produce the 180° phase shift required for oscillation.

phase splitter
Circuit that takes a single input signal and produces two output signals that are 180° apart in phase.

phonograph
Piece of equipment used to reproduce sound stored on a disk called a phonograph record.

phosphor
Luminescent material applied to the inner face of a cathode ray tube that when bombarded with electrons will emit light of various colors.

photoconductive cell
Material whose resistance decreases or conductance increases when exposed to light.

photoconduction
A process by which the conductance of a material is change by incident electromagnetic radiation in the visible light spectrum.

photodetector
Component used to detect or sense light.

photodiode
A semiconductor diode that changes its electrical characteristics in response to illumination.

photometer
Meter used to measure light intensity.

photon
Discrete portion of electromagnetic energy. A small packet of light.

photoresistor
Also known as a photoconductive cell or light dependent resistor. (LDR) A device whose resistance decreases with exposure to light.

photovoltaic cell
Component commonly called a solar cell used to convert light energy into electrical energy.

pi
Value representing the ratio between the circumference and diameter of a circle and equal to approximately 3.142.

pierce oscillator
A variation of the colpitts oscillator. This oscillator uses a quartz crystal in place of the inductor found in the colpitts oscillator feedback network. The crystal maintains a highly stable output frequency.

piezoelectric crystal
Crystal material that will generate a voltage when mechanical pressure is applied and conversely will undergo mechanical stress when subjected to a voltage.

piezoelectric effect
The production of a voltage between opposite sides of a piezoelectric crystal as a result of pressure or twisting. Also the reverse effect which the application of a voltage to opposite sides causes a deformation to occur at the frequency of the applied voltage. (Converts mechanical energy into electrical energy and electrical energy into mechanical energy.)

pinch-off region
A region on the characteristic curve of a FET in which the gate bias causes the depletion region to extend completely across the channel.

plastic film capacitor
Capacitor in which alternate layers of aluminum foil are separated by thin films of plastic dialectric.

plate
Conductive electrode in either a capacitor or battery. In vacuum tube technology, it is the name given to the anode.
Keywords : Electronic, Dictionary, Description, Info, What, Whatis, Introduction
Writer : delon  |
5 Jan 2006 Thr   
|  8.608 Views
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