Signal generators are mainly used to test or repair low-frequency amplifier’s frequency characteristic, gain, pass band in all kinds electrical instruments and meters. They are also be used as signal source of high-frequency signal generators.
What’s more, signal generators could provide AC signal voltage when calibrate electric voltmeter.
Principle of low-frequency signal generator: the system includes main vibration level, main vibration output regulating potentiometer, voltage amplifier, output attenuator, power amplifier, impedance converter (output transformer) and indicating voltmeter.
Signal generator is a kind of equipment that can provide various frequency, waveform and output level electrical signal.It can be used as signal source or excitation source when measuring amplitude characteristics, frequency characteristics, transmission characteristics and other electrical parameters of various telecom systems or telecom equipment, as well as measuring characteristics and parameters of components.
Signal generator is an electrical test signal instrument that produces the required parameters. It could be divided to four categories according to its signal waveform (1) sine waveform signal generators which are mainly used to measure frequency characteristics, nonlinear distortion, gain and sensitivity of circuits and systems. According to its different performance and application, it can also be divided into low frequency (20 hz to 10 MHZ) signal generator, high frequency (100 KHZ to 300 MHZ) signal generator, microwave signal generator, sweep and program control signal generator, frequency synthesis signal generator and etc. (2) function (waveform) signal generator which can produce some specific periodic time function waveform (sine wave, square wave, triangle wave, saw tooth wave and pulse wave, etc.) signal, the frequency range can be from a few micro-hertz to tens of megahertz. In addition to being used for communication, instrument and automatic control system test, signal generator is also widely used in other non-electric measurement fields. (3) pulse signal generator which can produce rectangular pulse with adjustable width, range and repetition frequency . It can be used to test the transient response of linear systems, or as an analog signal to test the performance of radar, multiplexed communications, and other pulsed digital systems. (4) Random signal generator. It is usually divided into noise signal generator and pseudo-random signal generator. The noise signal generator is mainly used for: introducing a random signal into the system under test to measure the system performance by simulating the noise in actual working conditions;In addition, a known noise signal is compared with the internal noise of the system to determine the noise coefficient.The random signal is used instead of sine or pulse signal to measure the dynamic characteristics of the system. When the correlation function is measured by noise signal, if the average measurement time is not long enough, statistical error will occur, which can be solved by pseudo-random signal.