Entries found for search: pulse
impulse response : Impulse response is the manner in which a device (usually a transducer of some sort) behaves after the initial energy input (sound) has stopped. An impulse is a signal or sound that has a very short, in fact, a vanishingly small, duration. A true mathematical impulse has zero duration and infinite amplitude, but still a finite amount of energy. The energy in an impulse is spread evenly over a wide frequency band, and this means that it can be used as a test signal to measure the characteristics of an audio device. The impulse response convolved with an input signal gives the output response.
pulse width : See duty cycle.
pulse-width modulation : See PWM.
pulse wave : A generic term for a variable rectangular waveform that varies between high (+) and low (-). The square wave is a pulse wave with a 1/2" (50%) duty cycle, therefore the value of every even-numbered harmonic is zero. A pulse wave with a duty cycle of greater than 1/2" has the same spectrum as a pulse wave whose duty cycle has the same denominator (e.g., a 1/3 has the same spectrum as a 2/3 duty cycle.) See PWM, Appendix C.
pulse : See beat, clock, difference tone, ppq, pulse wave, sync pulse, tach pulse, tempo, trigger.
pulse-code modulation : See PCM.
sync pulse : (1) The output of a clock used to keep synchronous devices, such as tape and video recorders, in synchronization. (2) The signal recorded by the sync head of a Nagra, derived from the camera motor through a sync cable, or from the Nagra’s own crystal sync generator. See FM sync.
tach pulse : A signal generated by the tachometer roller of an audio or video transport, one or more times per rotation. Because the tach roller is in contact with the tape in fast-wind modes as well as play or record mode, it can be used to get approximate tape location data when SMPTE timecode data cannot be read. Tach pulses sent by various decks to the synchronizer allow it to stop each deck near the SMPTE timecode designated by the engineer. Once in play or record modes, the decks will again interlock via the SMPTE timecode data. Tach pulses do not include location information, only speed and direction. Tach pulse is the mechanical, or analog, equivalent of word clock. See also bi-phase/tach."