Integrated oscillating infrared transmitter circuit

It is an oscillator and VT amplification driver stage composed of a six-inverter integrated circuit 74LS04 (CD4069) as the core. An RC oscillator composed of gate circuits IC1, IC2, Rz, RP, C, etc., its oscillation frequency depends on T=RC time constant, that is     , -1/D-1/[2. 2(RZ+RRP)C]     The oscillation frequency of the parameters shown in the figure is between 500 and 4000Hz. Adjusting the potentiometer RP can change the oscillation frequency. Gate circuits IC3 and IC4 are used for isolation, amplification, shaping and driving VT, so that the infrared light-emitting diode UD emits infrared pulse light. R is the current limiting resistor, and its resistance depends on the applied power supply voltage and the type of drive tube.