| 摘要 |
904,031. Controlling gain photo-electrically. PHILIPS ELECTRICAL INDUSTRIES Ltd. Nov. 21, 1958 [Nov. 26, 1957; May 8, 1958], No. 37559/58. Class 40 (3). [Also in Group XL (a)] The output of an amplifier 2 controls a light source (a neon glow tube) 6 which reduces the impedance of a photo-sensitive semi-conductor (e.g. cadmium sulphide) shunting the input if the input signal is large enough to overdrive the amplifier. Glass envelopes containing the light source and resistor may be fused together to form a single-unit (Fig. 2, not shown), or they may be in a cylindrical envelope 31 provided with a mesh 30 which allows passage of light from the glow tube 6 to the photo-register 4 while preventing capacitive transfer of voltage pulses from the one to the other. |
