The pulse width is a measure of the elapsed time between the leading and trailing edges of a single pulse of energy. The measure is typically used with electrical signals and is widely used in the fields of radar and power supplies. There are two closely related measures. The pulse repetition interval measures the time between the leading edges of two pulses but is normally expressed as the pulse repetition frequency (PRF), the number of pulses in a given time, typically a second. The duty cycle expresses the pulse width as a fraction or percentage of one complete cycle.
Pulse width is an important measure in radar systems. Radars transmit pulses of radio frequency energy out of an antenna and then listen for their reflection off of target objects. The amount of energy that is returned to the radar receiver is a function of the peak energy of the pulse, the pulse width, and the pulse repetition frequency. Increasing the pulse width increases the amount of energy reflected off the target and thereby increases the range at which an object can be detected. Radars measure range based on the time between transmission and reception, and the resolution of that measurement is a function of the length of the received pulse. This leads to the basic outcome that increasing the pulse width allows the radar to detect objects at longer range but at the cost of decreasing the accuracy of that range measurement. This can be addressed by encoding the pulse with additional information, as is the case in pulse compression systems.
In modern switched-mode power supplies, the voltage of the output electrical power is controlled by rapidly switching a fixed-voltage source on and off and then smoothing the resulting stepped waveform. Increasing the pulse width increases the output voltage. This allows complex output waveforms to be constructed by rapidly changing the pulse width to produce the desired signal, a concept known as pulse-width modulation.
The pulsewidth is a measure of the elapsed time between the leading and trailing edges of a single pulse of energy. The measure is typically used with...
signal. The pulsewidth ( τ {\displaystyle \tau } ) (or pulse duration) of the transmitted signal is the time, typically in microseconds, each pulse lasts....
{\displaystyle D} is the duty cycle, P W {\displaystyle PW} is the pulsewidth (pulse active time), and T {\displaystyle T} is the total period of the signal...
the servo a PWM (pulse-width modulation) signal, a series of repeating pulses of variable width where either the width of the pulse (most common modern...
duty cycle. The pulse wave is used as a basis for other waveforms that modulate an aspect of the pulse wave, for instance: Pulse-width modulation (PWM)...
operating systems or games, could play pulse-code modulation (PCM) sound through the PC speaker using special Pulse-width Modulation techniques explained later...
analog circuits. Simple bench pulse generators usually allow control of the pulse repetition rate (frequency), pulsewidth, delay with respect to an internal...
pulsewidth, the harmonic spectrum can be changed. The lowest THD for a three-step modified sine wave is 30% when the pulses are at 130 degrees width...
pulses twice for each revolution of the fan as a pulse train, with the signal frequency proportional to the fan speed Control input – a pulse-width modulation...
fraction of the time that the device is conducting may be adjusted so a pulse-width modulation output (or other frequency based modulation) can be obtained...
Stuart, who wrote software to modulate the duration of and between pulses (pulse-width modulation or "PWM", via a process now often referred to as "bit...
pulse cannot be narrower than the reciprocal of the pulsewidth. In the case of extremely short pulses, that implies lasing over a considerable bandwidth...
Gaussian pulse consistent with this spectral width would be around 300 picoseconds; for the 128 THz bandwidth Ti:sapphire laser, this spectral width would...
4 switches called Tucoplexing. Charlieplexing can even be used with pulse-width modulation to control the brightness of 12 LEDs with 4 pins. In the following...
Common modulation techniques include the carrier-based technique, or Pulse-width modulation, space-vector technique, and the selective-harmonic technique...
principally in the pulse duration. While lasers may output trains of short pulses to simulate a longer pulse, IPL systems can generate pulsewidths up to 250 ms...
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