A high-voltage pulse generator is an electronic device used to produce brief, rapid, repetitive shifts in high-voltage electronic signals. A wide variety of high-voltage pulse generators are used according to the specific application, with voltages ranging from hundreds of volts to more than one million. They are used in applications such as electronic product testing, communications, and scientific research.
The precise definition of high-voltage varies. For instance, the National Electrical Code used by the United States government defines high voltage in an electronic device as at least 600 volts. The International Electrotechnical Commission, a prominent international standards group, defines it as at least 1,000 volts for alternating current and 1,500 volts for direct current. A high-voltage pulse generator generally refers to a device that can produce voltage levels in at least the high hundreds or low thousands.
Portrayed visually on a graph, the waveform of a pulse generator's output resembles a series of squares or rectangles. When a pulse begins, the waveform shoots up in a nearly straight line to its new level, remains steady at that level for a brief time, and then drops back in a nearly straight line to the original baseline until the beginning of the next pulse. The time needed to shift from the lower level to the higher and back again are called the rise time and fall time, respectively, and the percentage of operating time spent at the higher level is called the duty cycle. The length of the pulse is called the pulse duration or pulse width, and the rate at which pulses occur is called the pulse repetition frequency. Depending on the high-voltage pulse generator being used and the function it is being used for, pulse durations can be as long as several minutes or as short as mere trillionths of a second (picoseconds).
One common application for high-voltage pulse generators is as electronic test equipment, used by designers and manufacturers to locate faults in electronic devices. Most pulse generators can produce pulses that vary in frequency, duration, and other characteristics. By producing pulses with different characteristics, a pulse generator allows a tester to observe how the device under test reacts to a variety of different inputs and identify potential problems that may arise during use.
The high-voltage pulse generator is important in radar, since the electromagnetic signal used by most modern radar to detect objects is pulsed rather than continuous. The pulse generator is part of a component called the modulator, which sends rapid pulses of power to the transmitter to produce pulsed radar waves. Pulse generators can be used for radio communications in the same way.