Core memory circuit

Claim 2

For a dynamic, nondestructive memory device comprising; a bistable electronic device having first and second input terminals and corresponding first and second output terminals; and a saturable magnetic core having a first input winding adapted to be connected to said first output terminal, a first output winding adapted to be connected to said second input terminal, and a second input winding; a power supply sensing and control unit comprising; a power supply sensing means for sensing the level of a power supply for said memory device; and control means comprising; means for grounding said first input terminal when said power reaches a first level on power turn on; means, actuated by said sensing means, for releasing said first input terminal from ground when a first predetermined level, higher than said first level, is reached by said power supply; means, actuated by said sensing means, for providing a pulse of energy to said second input winding when a second predetermined level, higher than said first predetermined level, is reached by said power supply; means, actuated by said energy pulse, for electrically connecting said first output winding to said second input terminal, following a fixed delay after the onset of said energy pulse; means, actuated by said sensing means, for connecting means for transmitting the state of said flip-flop to said core when the power supply falls to said second predetermined level on power turnoff, and for disconnecting said transmitting means when the power supply falls to said first predetermined level on power turnoff; means for disconnecting said transmitting means at all other times; and means, actuated by said sensing means, for grounding said first input terminal when said power supply falls to said first predetermined level on power turnoff.

Claim 3

A power supply sensing and control unit as defined in claim 1 wherein said power supply sensing comprises a first Zener diode and a second Zener diode; the cathode terminals of said first and second Zener diodes being connected to the positive terminal of said power supply; said first Zener diode being conductive only at and above said first predetermined level; said second Zener diode being conductive only at and above said second predetermined level.

Claim 4

A power supply sensing and control unit as defined in claim 2 wherein said means for grounding said first input when said first level is reached on power turn on, and for releasing said first input terminal from ground when said first predetermined level is reached on power turn on; and for grounding said first input terminal when the power supply falls to said first predetermined level on power turnoff, comprises; a first transistor having its base lead connected to the anode of said first Zener diode, and its collector lead connected to the input of a first inverter gate; the output of said first inverter gate being connected to said first input terminal; said first level being the level at which said gatE is activated; whereby, when said first level is reached, but said first predetermined level is not reached, on power turn on, said first Zener diode is nonconductive, causing said first transistor to be nonconductive, causing the input to said first inverter gate to be grounded; and whereby, when said first predetermined level is reached on power turn on, said first Zener diode becomes conductive, causing said first transistor to become conductive, causing the input to said first inverter gate to go low, causing the output of said first inverter gate to be lifted from ground; and whereby, when said power supply falls to said first predetermined level on power turnoff, said first Zener diode becomes nonconductive, causing said first transistor to be nonconductive, causing the input to said first inverter gate to be high, causing the output of said first inverter gate to be grounded.

Claim 5

A power sensing and control unit as defined in claim 3 wherein said means for providing a pulse of energy to said second input winding when said second predetermined level is reached on power turn on, and for connecting said first output winding to said second input terminal following a fixed delay after the onset of said pulse, comprises; a second transistor having its base lead connected to the anode of said second Zener diode and it collector connected to the input of a second inverter gate; the output of said second inverter gate being connected to the base lead of a third transistor whose collector lead is connected to one input of a first NAND gate, the output of said first NAND gate being connected to the input of a third inverter gate, the output of said first NAND gate being further connected to one end of said second input winding, the other end of said second input winding being connected to the positive terminal of said power supply, the output of said third inverter gate being connected, through a first capacitor, to the second input of said first NAND gate; the junction of said first capacitor and said other input of said first NAND gate being connected, through a first resistor, to ground; the output of said third inverter gate being further connected to the input of a fourth inverter gate; the output of said fourth inverter gate being connected to one end of said first output winding, the other end of said first output winding being connected to said second input terminal; the output of said fourth inverter gate being further connected, through a second capacitor, to ground; whereby, when said second predetermined level is reached on power turn on, said second Zener diode becomes conductive, causing said second transistor to become conductive, causing the input to said second inverter gate to go low, causing the output from said second inverter gate to go high, causing said third transistor to become conductive, causing the input to said first NAND gate to go low, causing the output of said first NAND gate to go high and to thereby provide a pulse of energy to said second input winding, the duration of said pulse being determined by the interaction of said first NAND gate, said third inverter gate, said first resistor and said first capacitor; and whereby when the output of said first NAND gate goes high, the output of said third inverter gate goes low, causing the output of said fourth inverter gate to tend to go high and thereby apply a positive potential to one end of said first output winding, said positive potential being delayed for said fixed delay by the action of said second capacitor.

Claim 6

A power sensing and control unit as defined in claim 4 wherein said memory device further comprises; a fourth transistor having its collector lead connected to one end of said first input winding, the other end of said first input winding being connected to the positive potential of said power supply; the base lead of said fourth transistor being connected to the anode terminal of a first and a second diode; the cathode terminal of said first diode being coNnected to said first output terminal; and wherein the means for connecting the means for transmitting the state of said flip-flop when said power supply falls to said second predetermined level on power turnoff, comprises; said second Zener diode, said second transistor and said second inverter gate; the output of said second inverter gate being connected to the input of a fifth inverter gate; the output of said fifth inverter gate being connected to the cathode lead of said second diode; whereby, when said level falls to said second predetermined level on turnoff, said second Zener diode becomes nonconductive said second transistor to become nonconductive, causing the input to said second inverter gate to go high, causing the output from said second gate to go low, causing the output from said fifth gate to go high, causing said second diode to become nonconductive; and wherein, when said first output terminal is high, said first diode becomes nonconductive, causing said fourth transistor to become conductive; but when said first output terminal is low, said first diode is conductive so that said fourth transistor is nonconductive.

Claim 7

A power supply sensing and control unit as defined in claim 5 wherein said means for disconnecting the means for transmitting the state of the flip-flop when said power supply level falls to said first level on turnoff, comprises; said first Zener diode, said first transistor, and said first inverter gate; the output of said first inverter gate being connected to one input of a second NAND gate; the output of said second NAND gate being connected to the input of a sixth inverter gate; the output of said sixth inverter gate being connected to the cathode lead of said second diode; wherein, when the power supply level falls to said first predetermined level on power turnoff, said first Zener diode is nonconductive, causing said first transistor to become nonconductive, causing the input to said first gate to go high, causing the output from said first gate to go low, causing the output from said sixth gate to go low, causing said second diode to become conductive.

Claim 8

A power supply sensing and control unit as defined in claim 6 wherein the means for keeping said means for transmitting the state of said flip-flop to said core disconnected at all times subsequent to power turn on, but prior to the time that the power supply level falls to said second predetermined level on turnoff, comprises; said first Zener diode, said first transistor, said first inverter gate, said second NAND gate, said sixth inverter gate, said second Zener diode, said second transistor, said second inverter gate, said fifth inverter gate, and a third NAND gate; the collector of said second transistor being connected to one input of said third NAND gate; the output of said second NAND gate being connected to the other input of said third NAND gate; the output of said third NAND gate being connected to the other input of said second NAND gate; whereby the output of either said fifth inverter gate or said sixth inverter gate is kept low at all times subsequent to power turn on after said first level is reached and until said power supply level.