Magnetic saturable-core timing device

Accurate timing devices are fundamentally important in both industial and military control applications. This paper deals with electric timing apparatus in which the timing sense is derived from the volt-second time integral required to saturate a saturable magnetic core. Discrete time periods may be generated on the basis of this principle. In this paper, fundamental design equations are presented and basic circuitry is described. Specific applications are discussed which make use of transistors in the switching mode. Transistors afford convenient means for operating various electric circuits as a function of the time period defined by the controlled saturation of the magnetic cores. The transistors contribute no appreciable time delay in the circuit. The problems associated with environmental variations in transistors and cores are discussed, and possible methods of compensation are presented.