WIRELESS TRANSMITTING/RECEIVING UNIT FOR TRANSMITTING AN ACOUSTIC EMISSION SIGNAL, CONCERNED WITH CONVERTING A WEAK SIGNAL DETECTED FROM AN ACOUSTIC EMISSION INTO AN OPTICAL SIGNAL AND TRANSMITTING THE OPTICAL SIGNAL WIRELESSLY

摘要

PURPOSE: A wireless transmitting/receiving unit for transmitting an AE(Acoustic Emission) signal is provided to convert a signal detected by an AE sensor into an optical signal and wirelessly transmit and receive it. CONSTITUTION: An AE sensor(5) detects an infinitesimal signal. An amplifier(11) amplifies the detected signal. A BPF(Band-Pass Filter)(13) cancels noise from the amplified signal and filters it. A V/F converter(17) converts an analog signal into a pulse wave frequency. A buffer(19) amplifies a signal outputted from the V/F converter(17). An LED(Light Emitting Diode) generates an optical signal. A photo transistor(22) is conducted according to the optical signal of the LED(12). A Schmitt trigger(21) is operated when a signal outputted from the photo transistor(22) is in a certain range of voltage level. A logical circuit(23) outputs a signal outputted from the Schmitt trigger(21) as a pulse wave frequency. An F/V converter(25) converts to an equivalent analog voltage according to a frequency outputted from the logical circuit(30). An A/D converter(30) converts the analog voltage into a digital signal and transfers it to a computer.