Detector for fault of receiver

Abstract

Abstract PURPOSE:To set optionally an input threshold field level, by comparing the signal, which is obtained by synthesizing weighted results of a noise from a demodulator and a limiter current of the intermediate frequency stage, with a reference level. CONSTITUTION:An I -V converting circuit 6 convers the output current of a limiter provided in the intermediate frequency stage to an equivalent voltage signal, and the output voltage of the circuit 6 is increased when the limiter current is increased according as the input field is increased. The output of the circuit 6 is weighted by a variable resistance 4 and is applied to a synthesizing circuit 1. The noise generated by a noise amplifying and rectifying circuit 7 is weighted by a variable resistance 5 and is applied to the synthesizing circuit 1. The output of the circuit 1 is inputted to a comparing circuit 3 together with the reference voltage of a reference voltage generating circuit 2. Thus, the synthesized output level is changed to detect a fault early even if the gain of a receiver is reduced while keeping the input threshold field level for fault detection constant.

Inventors

• 👤 Mitsuru Ishii
• 👤 満 石井

Bibliographic Details