protection against unwanted ausstroemen of gases from a previously hochevakuierten space into a connected, also hochevakuierten area in the case of the collapse of the vacuum in the first room

摘要

713,231. Radio receiving circuit. PHILIPS ELECTRICAL INDUSTRIES, Ltd. June 24, 1952 [June 27, 1951], No. 15884/52. Class 40 (5) In a muting circuit, noise voltages from a receiving channel 1, 2 are passed from the output of the detector to a noise amplifier 6, via a high-pass filter comprising a condenser 5 and resistance 15. The amplified noise is rectified by a diode 9 and the voltage appearing across the diode load resistance 10 is applied via a filter network 17 to block a low-frequency stage 4 in the receiving channel. The muting is removed upon reception of a signal by the reduction in noise which then occurs. Release of the receiving channel is made more rapid by opposing to the bias developed across resistance 10 a fixed bias which is derived from an adjustable resistance 8 in the cathode circuit of the valve 6. The cathode potential of the valve 6 may be stabilized by means of a resistance 23 connected to the screen grid circuit. In order to prevent the application of positive potentials to the grid of the valve 4, a limiter diode 24 is connected across the output of the filter 17.