Ultrasonic flow detection circuit

The invention discloses an ultrasonic flow detection circuit. The ultrasonic flow detection circuit consists of an ultrasonic source signal generation circuit, a signal transmitting and receiving circuit, a detection circuit, a phase detection circuit, a phase-to-voltage conversion circuit and a 12-bit analog-to-digital (AD) module of a micro processor. During measurement, the ultrasonic source signal generation circuit generates a 1MHZ signal and keeps the whole fair current and adverse current measurement process; an ultrasonic transducer receives an ultrasonic signal and filters out noise and an interference signal through the detection circuit; the signal is compared with a reference signal through the phase detection circuit so that a phase difference is generated; the phase-to-voltage conversion circuit converts a measured signal into a voltage signal; and a voltage value is measured through the high-precision AD conversion of the micro processor. As the fair current transmission speed and the adverse c