thumb|250px|a simple analog function generator, circa 1990   a function generator is usually a piece of electronic test equipment or software used to generate different types of electrical waveforms over a wide range of frequencies. some of the most common waveforms produced by the function generator are the sine, square, triangular and sawtooth shapes. these waveforms can be either repetitive or single-shot (which requires an internal or external trigger source).cnx.org - using a basic function generator, 2005-08-21 integrated circuits used to generate waveforms may also be described as function generator ics. although function generators cover both audio and rf frequencies, they are usually not suitable for applications that need low distortion or stable frequency signals. when those traits are required, other signal generators would be more appropriate. some function generators can be phase-locked to an external signal source (which may be a frequency reference) or another function generator. function generators are used in the development, test and repair of electronic equipment. for example, they may be used as a signal source to test amplifiers or to introduce an error signal into a control loop. == electronic instruments == === working === simple function generators usually generate triangular waveform whose frequency can be controlled smoothly as well as in steps. this triangular wave is used as the basis for all of its other outputs. the triangular wave is generated by repeatedly charging and discharging a capacitor from a constant current source. this produces a linearly ascending or descending voltage ramp. as the output voltage reaches upper and lower limits, the charging and discharging is reversed using a [[compa
Electronic_test_equipment