An information memory with at least one storage element containing a tunnel diode

摘要

953,549. Tunnel diode bistable circuits. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Aug. 3, 1961 [Aug. 10, 1960], No. 27733/60. Heading H3T. [Also in Division G4] A tunnel diode binary storage unit comprises (Fig. 2) two potential dividing circuits R1, R2, R5 and R4, R3, R5 with the tunnel diode TD connected to a tap A. Writing is by application of a positive pulse followed by a negative pulse at point 3 which if point 1 is held negative will switch TD first to its low-voltage and then to its high voltage state (since R5 is large TD operates as a constant current bistable element). If L is held at earth potential the negative pulse will be by-passed and TD will be left in its low-voltage condition. Interrogation is non-destructive; a negative pulse at 4 insufficient to switch TD will, if it is in its high voltage state, lower the potential at D2 sufficiently for the latter to conduct and provide an output at 2. Fig. 3 shows a matrix of units into which a row of data can be written by supplying a signal on an " S " wire and selectively energizing the appropriate " W " column lines. An interrogation pulse on an " I " line provides outputs at R.