Ultrasonic transmitter circuit a composed of UCM-40-T and 74LS00 NAND gate

It is an ultrasonic transmitter circuit composed of a 74LSOO 412 input A and non-r circuit . Among them, Fl, Wei and C form an oscillation
circuit to generate a 40kH oscillation signal. After being modulated by F2, it is sent to the F3 excitation circuit to drive the sensor UCM-40-T to work and send out ultrasonic
signals.
    In this circuit, Fl and F3 are connected as a NOT gate, and F2 is used as a NAND gate , which is beneficial to the introduction of modulation signals. From this point of view, this circuit
has a simple structure and is easy to debug. It only needs a 74LSOO chip to complete the tasks of oscillation, modulation, excitation and emission of ultrasonic waves at the same time.
The oscillation period of this circuit is determined by the product of Rz and C, and its calculation formula is t oscillation period T-2.2R. C, the parameter aklt will be substituted for A, and its oscillation frequency is about
40kHz. You can also change the values ​​of R and 'C to select other required oscillation frequencies.