| 摘要 |
<p>A Doppler-effect movement detector for application as an intruder alarm with a transmitter oscillator energising a transmitting transducer, and a receiving transducer feeding a signal to a receiver followed by an amplifier and demodulator which also is fed with a signal from the transmitting oscillator unit consists of a standard broadcast receiver unit having terminals for a resonant circuit, and the signal from the transmitting oscillator are fed to these terminals, or a stand broadcast receiver unit with a differential input which is fed from the receiver and the transmitter oscillator.</p> |
