Junction-transistor circuits for analogue-to-binary code conversion

Summary form only given. This paper describes a voltage comparator which uses a junction transistor and a silicon diode. The comparator circuit is essentially a blocking oscillator which generates a sharp output pulse when the input waveform passes through the reference level. By taking advantage of the special properties of the semiconductor devices, the comparator can be designed to have an accuracy of ± 5 millivolts throughout a temperature range of 20°C to 4OO.C. A theoretical analysis of the comparator is given with particular emphasis placed on accuracy and switching speed. It is shown that by preceding the voltage comparator with a transistor dc summing amplifier, the reference level for the comparator may be adjusted over a range of ± 25 volts