Due to the large frequency range, the frequency selection network uses three sets of capacitors with different capacities to form three frequency bands, which are selected by the band switch, and then the coaxial potentiometer adjusts the oscillation frequency. The frequency of the signal is determined by the RC frequency selection network of the sinusoidal oscillation circuit. To keep the triangle wave output amplitude unchanged and good linearity, the integration time constant must be changed at the same time.įigure 2.

The reason is that if the time constant of the integration circuit does not change, the amplitude of the output triangle wave changes at the same time as the frequency of the square wave signal changes. This circuit has a simple structure and can produce good sine and square wave signals, but it is difficult to generate a synchronized triangular wave signal through an integration circuit. Among them, the sine wave is generated by the RC bridge oscillation circuit, which is characterized by stable amplitude and frequency and easy adjustment, and can generate a sine signal with a very low frequency then a zero-crossing comparator is used to generate a square wave, and then an RC integration circuit is used to generate a triangular wave. Here, the sine wave→square wave→triangle wave scheme shown in Figure 2 is used. There are many schemes for waveform generation and transformation. Through Proteus software simulation and simulation experiment, the ideal waveform of 20Hz~20kHz is obtained, and the frequency and amplitude of the signal can be adjusted. In this blog, quad-operational amplifiers with differential input LM324 are used as the core device, a sine wave is generated by an RC bridge oscillation circuit, then a square wave is generated by a zero-crossing comparator, and a triangular wave is generated by an integrating circuit. Some standard products that are widely used at present, although they have complete functions and high-performance indicators, are more expensive and have many functions that are not available. It is widely used in production practice and technology. The circuit form can be composed of op-amps and discrete components, or a single-chip integrated function generator. The wave generator refers to an instrument that generates electrical test signals with the required parameters. LM324 Quad-Operational Amplifiers 1.2 What is Wave G enerator ? And the frequency and amplitude of the signal can be adjusted.įigure 1. It can output the sine wave, square wave and triangle wave signals commonly used in experimental testing. The low-frequency signal generator designed with it as the core device has the advantages of simple circuit, stable waveform, economical and practical, and easy to use. LM324 is a low-cost quad-operational amplifier.

Voltage comparator lm339 proteus