This production is a signal generator with integrated circuit ICL8038 as the core device. The chip can output square wave, triangular wave and sine wave at the same time, with large frequency adjustment range, small waveform distortion and strong practicability.
1. Power supply
It is composed of transformer T, bridge stack, capacitors C1 ~ C4 and three terminal voltage regulators l7812 and L7912, which can provide ± 12V stable power supply voltage.
2. Signal generator
ICL8038 can output square wave, triangular wave and sine wave at the same time. When in use, only a small amount of resistance and capacitor elements need to be connected externally. Rp5 is the square wave output duty cycle adjustment resistance with a resistance value of 4.7K Ω, which is used to change the voltage of pins 4 and 5, so as to change the square wave duty cycle. RP1, RL and R2 form a voltage dividing network. RP1 is a frequency adjustment potentiometer. The potentiometer uses a high-quality multi turn potentiometer with a resistance of Lok. Adjust RP1 and change the 8-pin input voltage of ICL8038 to change the frequency of the output waveform; C6 ~ CLL are external timing capacitors. By changing the position of switch S2, the output signals of 6 frequency bands (0 ~ 20Hz, 20Hz ~ 200Hz, 200Hz ~ 2KHz, 2KHz ~ 20kHz, 20kHz ~ 200kHz, 200khz-1mhz) can be obtained; RP3 and RP4 are sine wave distortion adjustment potentiometers. In order to reduce the distortion of sine wave, ICL8038 adopts two sets of fine-tuning networks RP3 and RP4 to fine tune the potential of pin 1 and 12 respectively to minimize the distortion of sine wave signal. ICL8038 outputs sine wave at 2 pins, triangle wave at 3 pins and square wave at 9 pins.