磁気変調式直流増幅器とその応用

抄録

Electronic control system requires a very reliable D. C. amplifier of high gain, high response and yet low noise. Magnetic modulator type D. C. amplifier is very reliable, but the amplifier of 100c/s carrier type does not satisfy all of the above requirements. Instead or 100c/s type, therefore, 1 000c/s type is employed. This D. C. amplifier consists of a 500 c/s oscillator, magnetic modulator, 1 000c/s tuned amplifier and power amplifier. The oscillator and amplifiers are transistorized. As a result of using the 1 000c/s carrier type, the following characteristics have been obtained:
1) Gain: 8×10⁴ (mA/mA)
2) Cut off frequency: 20c/s
3)Noise level: 5×10^-16W (i.e.0.002μA)
4) Ambient temperature: -10°C-+70°C
Also described are the applications of this D. C. amplifier to an electronic control system and electrical interference caused by A. C. power line.