A negative resistance for D.C. computers

A d.c. negative resistance suitable for use in analogue computers is described. The circuit uses two transistors and eight resistances and is compensated against unbalance in the two transistors. A nomogram has been constructed to simplify the design of the circuit for any required value of negative resistance. There is also a discussion of the properties of, and the differences between series and shunt type of negative resistances. The circuit described gives a shunt type of negative resistance.