a binary - to - ternary converter arrangement which achieves protective resistance against high outside voltages without having to compromise the voltage level of the positive and negative output ternary pulses . in so achieving , the minimum amplitude requirement of a ccitt recommendation of an output pulse for a given supply voltage is satisfied . this converter arrangement includes a parallel circuit of first and second series circuits . the first series circuit forms a main current path of two transistors and the second series circuit forms a current path of a diode , two resistors , and a third transistor . the different elements of these two circuits , along with a capacitor element , are interconnected in such a way as to eliminate the need for the use of a transformer altogether . the control electrodes of the first and second transistors serve as input ports and the junction port of the two resistors serves as the output port .