Saturday, 20 April 2024, 5:43 AM
Site: edulabs.org academy
Course: Activity Examples (Activity Examples)
Glossary: Electronics (Mike Jaroch)
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PERIOD TIMEThe time required to complete one cycle of a waveform [2] [10] [12]. |
PERIODIC WAVEA waveform that undergoes a pattern of changes, returns to its original pattern, and then repeats the same pattern of changes. Examples are square waves, rectangular waves, and sawtooth waves [9]. |
PERMANENT MAGNET SPEAKERA speaker with a permanent magnet mounted on soft iron pole pieces [17]. |
PERMEABILITYThe measure of the ability of a material to act as a path for magnetic lines of force [1] [8]. |
PERSISTENCEThe length of time a phosphor dot glows on a CRT before disappearing [6] [18]. |
PHANTASTRONA variable-length sawtooth generator often used to produce a sweep on an A-scope [18]. |
PHASEThe angular relationship between two alternating currents or voltages when the voltage or current is plotted as a function of time. When the two are in phase, the angle is zero; both reach their peak simultaneously. When out of phase, one will lead or lag the other; that is, at the instant when one is at its peak, the other will not be at peak value and (depending on the phase angle) may differ in polarity as well as magnitude [2]. |
PHASE ANGLEThe number of electrical degrees of lead or lag between the voltage and current waveforms in an ac circuit [2] [12]. |
PHASE MODULATION(pm)—Angle modulation in which the phase of the carrier is controlled by the modulating waveform. The amplitude of the modulating wave determines the amount of phase shift, and the frequency of the modulation determines how often the phase shifts [12]. |
PHASE SHIFTERA device used to change the phase relationship between two ac signals [11]. |