抄録
Ternary fail-safe logic systems have an important advantage in that the systems can clearly distinguish a failure state corresponding to a truth value φ from normal signals corresponding to truth values 1 and 0. For practical fail-safe systems both safety and reliability are required. The magnetic core itself has high reliability and is suited for a ternary fail-safe logic element.
This paper presents a practical realization of ternary Φ type fail-safe logic circuits using ferrite cores. Various functions such as NOT, OR, AND, Delay, NOR and NAND which are fail-safe can easily be obtained by using ferrite cores. The equivalent circuit in a magnetic circuit may be drawn from the measured values on the reciprocal of switching time versus the applied pulse amplitude which is well known as a basic characteristic of a core. On the basis of the equivalent circuit obtained thus, operations of fail-safe logic circuits can be made clear. A practical realization of the failsafe logic function X+Y is shown as an example.
