Working Principle of Function Signal Generator

The function signal generator system is mainly composed of a master oscillator, a master oscillator output adjustment potentiometer, a voltage amplifier, an output attenuator, a power amplifier, an impedance converter and an indicating voltmeter. When a small signal sine wave is input to the input end, the signal is transmitted in two ways, one to complete the rectification and voltage doubling function to provide working power; the other enters the input end of an inverter to complete the signal amplification function. The amplified signal is processed by the gate circuit of the subsequent stage, converted into a square wave and output, and the output end is an adjustable resistor.

Working Principle of 5G8038 Function Generator

With the continuous development of integrated manufacturing technology, multifunctional signal generators have been made into special integrated circuits. This integrated circuit is easy to use, simple to debug, and has stable performance. It can not only generate sine waves, but also triangle waves and square waves. 5G8038 is one of them. It can be combined with operational amplifier LM318, resistors and capacitors to realize a signal generator with multiple waveform outputs.

8038 Function Generator Block Diagram:

It consists of a constant current charge and discharge oscillator circuit and a sine wave converter. The constant current charge and discharge oscillator generates square waves and triangular waves, and the triangular wave outputs a sine wave through the sine wave converter. The two comparators C1 and C2 in the figure form a window comparator with reference voltages set at 2/3Vcc and 1/3Vcc respectively. The outputs of the two comparators control the position end and reset end of the RS trigger respectively. The two constant current sources I1 and I2 are responsible for charging and discharging the timing capacitor C, and the conversion between charging and discharging is controlled by the output of the RS trigger through the on or off of the electronic switch S.

The circuit design is I2=2I1. When the electronic switch S is turned off, the circuit charges the external capacitor C. When the electronic switch S is turned on, the capacitor C discharges, so a triangular wave with good linearity is generated on the capacitor C and output from pin 3 through the buffer. In order to obtain the conversion from triangular wave to sine wave in a relatively wide frequency range, a broken line approximation conversion network composed of resistors and transistors converts the triangular wave into a sine wave and outputs it from pin 2. The signal used to control the switch S and the output of the RS trigger is a square wave, which is output from pin 9 through the buffer.