A Transistorized Fail-Safe Trip Amplifier

This paper describes a novel transistorized fail-safe trip amplifier to use in the control of nuclear reactor. The trip unit is inherently safe by virtue of the trip point being independent of the amplifier gain, since its out-put is zero, when the signal exceeds or equals the trip setting. The trip setting may be changed over the range of 0-5 volts, the unit can be used as a low or high level and high-low trip. The amplifier has a dynamic input current range 10-3 - 10-6 Amps and the drift of the unit is less than 10-9 Amps for long term and temperature variation, accuracy and stability better than ± 0.1 %.