Special type of emitter-coupled rectangular pulse generator

A new type of emitter-coupled multivibrator having only condensers in the base circuit has been designed and the performance behaviour has been discussed on the basis of the circuit conditions which make the two transistors alternately conducting and non-conducting. Charging of the base capacitors due to forward base currents and their discharge due to reverse base currents of the two transistors have been taken into consideration to explain the performance behaviour of the new type of multivibrator. The circuit is capable of generating fairly good rectangular pulses (if a relatively large value condenser is used at the base of one of the transistors) of quite small rise and fall times by taking suitable values of the circuit components. Expressions for the time periods of conduction of transistors X1 and X2 of the proposed set-up have been developed by taking C2 considerably greater than Cj.