Servo-Type Transistor Analog-Digital Converter
Kunihiko ICHIKAWA, Taiji AIZAWA · Transactions of the Japan Society of Mechanical Engineers · 1960
Servo-type analog-digital converter is a converter whose output (digital) is to follow the input (analog) on the same principle as the automatic balancing instrument works. In this converter, there are three principal components ; that is, counter conversion of digital to analog value (decoder), amplification of error between input and counter-converted analog value, and logical circuits which control the counting action of reversible counter according to the amplified voltage signal. The tentative converter is remarkable in three aspects. First, it has a stable AC amplifier working on the high carrier frequency transistor chopper. Second, output of amplifier is not demodulated to DC voltage, but is connected as it stands to the logical circuit, and so the response speed is very high. Third, decoder, using the MIT-type network, is a purely electronic network with transistors only as active elements.