Multivibrator system for logic circuits

963,159. Transistor two-state trigger circuits. SOCIETE DE DIFFUSION D'EQUIPEMENTS ELECTRONIQUES, S.D.E.E. March 30, 1962 [March 30, 1961], No. 12270/62. Heading H3T. A two-state trigger circuit comprising two alternatively conducting transistors, changes its state in response to a signal and remains in that state or returns to the original state at the end of the signal in dependence upon the condition of a control signal applied through a diode to one base electrode. The circuit shown has a normal state in which transistor T1 is conducting, being switched to the state on first applying the power by a capacitor C5, as described in Specification 915,762. The circuit may be switched to the other state by varying the voltage at terminal 7 as by connecting it to the positive supply source terminal 10 by switch I2 directly or through a resistor X. The circuit will return to its initial state on removal of this voltage, unless terminal 8 has been connected to a suitable potential source, as by operating switch I1 to connect the terminal directly or through a resistor to the positive terminal 10. Outputs for operation of further stages may be obtained from terminals 1-4 and 12-15 and the common emitter resistor R1 may be decoupled by a capacitor common to other circuits. A diode D1 isolates output terminals 12-15 from the base of transistor T1 when T2 is non-conducting. A suitable input circuit arrangement is described with reference to Fig. 2 (not shown).