Condition warning memory circuit

Claim 2

For use with a system providing a signal corresponding to a condition, apparatus comprising: a reference signal source; means connected to the reference signal source and responsive to the signal therefrom for providing first and second calibrating signals; means connected to the system and to the calibrating signal means for comparing the conditiOn signal to the first and second calibrating signals and providing operating outputs in accordance with said comparison; condition warning means; and means connected to the comparison means and to the condition warning means for applying the operating outputs to operate the warning means when the condition signal is at a predetermined critical level.

Claim 3

Apparatus as described by claim 1, wherein the means connected to the reference signal means and responsive to the signal therefrom for providing the first and second calibrating signals includes: a network including a plurality of resistors connected in parallel; switching means connected to the reference signal source and selectively connected to one of the plurality of resistors for applying the reference signal through said resistor to provide the first calibrating signal at an output of the network; signal divider means connected to the resistor network output and responsive to the first calibrating signal for providing the second calibrating signal; and the first calibrating signal corresponding to the second calibrating signal plus a predetermined constant commensurate with the predetermined critical level of the analog signal.

Claim 4

Apparatus as described by claim 2, wherein the means connected to the system and to the calibrating signal means for comparing the condition signal to the first and second calibrating signals and providing operating outputs in accordance with said comparison includes: first means connected to the system and to the resistor network for comparing the signals therefrom; second means connected to the system and to the signal divider for comparing the signals therefrom; the first and second means being ineffective for providing operating outputs when the condition signal is equal to or less than the second calibrating signal less the predetermined constant; the second means providing an operating output when the condition signal equals the second calibrating signal; and the first and second means providing operating outputs when the condition signal is equal to or greater than the first calibrating signal.

Claim 5

Apparatus as described by claim 3, wherein; the operating output provided by the first means overrides the operating output provided by the second means.

Claim 6

Apparatus as described by claim 3 wherein the means connected to the comparison means and to the condition warning means for applying the operating outputs to operate the warning means when the condition signal is at a predetermined critical level includes a current flow control circuit, said circuit comprising: first current flow control means connected to the second means and to the warning means for passing the operating output from said second means to operate the warning means; and second current flow control means connected to the first means and to the first current flow control means and responsive to the operating output from the first means for maintaining the first current flow control means effective to pass the output from the first means.

Claim 7

Apparatus described by claim 3, wherein the current flow control circuit includes: third current flow control means; and fourth current flow control means connected to the first means and to the third current flow control means and affected by the operating output from said first means for latching third current flow control means conductive.