A pulse generator is a hardware device that outputs an electrical signal at a certain frequency at regular intervals. Pulse generators are used in varying capacities to test equipment and may output several wave forms, most commonly square waves or sine waves. Most pulse generators have controls that can change pulse period, width, repetition frequency and shape.
The time between two waveforms created by a pulse generator. The delay parameter can be changed for the purpose of testing various types of equipment or to pinpoint errors in a system.
Double Pulse Spacing
An option on some pulse generators that allows an output of dual identical pulses followed by spacing. Typically used to simulate real-life double pulses, which can occur on some equipment, or to test recovery times.
A setting on pulse generators that allows the creation of both positive and negative polarity pulses. Useful when testing different types of systems.
Duty Cycle or Duty Factor
The percentage of time that a pulse generator is outputting a signal. A 50 percent duty cycle would be a square wave, as the wave form would be high for half of the time and at 0 for half of the time that the pulse generator is operational. Many pulse generators have variable duty cycles.
Full Width at Half Maximum (FWHM)
FWHM is used to designate when the power in a system is at least half of the maximum power. In relation to a pulse generator, FWHM would refer to the width and power attenuation of pulse waves that are used to test a system.
Modulation in pulse generators generally refers to pulse width modulation, a setting on the generator that allows pulses to be created with varying width.
Pulses are determined to be coincident if they arrive at the same time or what is accepted by a system to be within a given range. Useful in testing a coincidence circuit.
The total time from when a pulse generator starts generating a pulse to when the next pulse begins, or, when dual pulses are generated, the time to the next new period of pulses. Not to be confused with pulse duration, which is the time that a pulse is active.
Pulse Repetition Frequency
The frequency at which a complete pulse period is completed. Pulse repetition frequency is often controllable or programmable in modern pulse generators.
The difference between the stated output of a pulse generator and its real output. A low number indicates a better pulse resolution.
Pulse Width or Pulse Duration
The time that a pulse is "on" or active is referred to as its width. Wider pulses might be desirable for different purposes. A setting on many pulse generators allows users to change the generated pulses by altering the width of each pulse.
A type of wave that regularly alternates between two levels with a 50 percent duty cycle. Most pulse generators can be used to generate square waves for the purpose of testing various types of equipment.
A system's response to a step function that causes a change in inputs from zero to one.
Transition Time or Rise Time & Fall Time
The total time of the rise and fall of each pulse created by a pulse generator. For example, the transition time of a perfect square wave would be 0, as square waves alternate instantaneously between two states. On the other hand, a sine wave would always have a transition time higher than 0.
Variable Pulse Width
Wider or narrower pulse widths might be desirable for testing certain types of equipment. Pulse generators with variable pulse width generally have a wider range of applications and can be more useful for testing complex systems.