GB1153270A - Improvements in or relating to Bistable Circuits - Google Patents

Abstract

1,153,270. Bi-stable circuits. TELEFUNKEN PATENTVERWERTUNGS G.m.b.H. 22 March, 1968 [25 March, 1967], No. 13881/68. Heading H3T. In a bi-stable circuit comprising two crosscoupled transistors of one conductivity type with a common emitter resistance, each transistor is connected anti-parallel with another transistor of opposite conductivity type, the bases of the latter transistors being connected together and receiving the input signal, thereby steering it to the appropriate transistor of the bi-stable pair. In Fig. 2, if transistor 1 is conductive and transistor 2 is cut-off, an input signal 6, through capacitor 16, applied to the base of control transistor 13, causes it to conduct, thus increasing the voltage drop across resistor 11 and decreasing that across resistor 10. By a cumulative effect, transistor 2 becomes conductive and transistor 1 is cut-off, with control transistor 12 held at the limit of the pass region by the value chosen for resistor 15 of the voltage divider shown as resistor 15 and 14. In Fig. 3 (not shown), the collector of transistor 13 is taken to a reference potential through a resistor 17 across which an output signal of half the input frequency can be obtained.