Fail-safe monitoring system
OwnerJack A. Bryantinventor
Life of this patent
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Abstract
A fail-safe system for monitoring a condition and activating controls in response either to the non-existence of that condition or the failure of any component in the system, in which a preliminary fail-safe oscillation train derived from sensing the condition is converted into a steady state indication of that condition, and a secondary fail-safe oscillation train is generated in a fail-safe way from said steady state indication for further transmission downstream for control purposes. In the context of flame monitoring, means associated with the preliminary oscillation train are provided for discriminating between separate flames and for time delay purposes.
Claims3
A fail-safe system for detecting whether or not a given variable physical condition exists in a given one of a plurality of possible states and for holding an on-off type control in the on state only while said given one state continues, comprising:
- (a) means for detecting the existence of said given one state and for generating an oscillating electrical signal only while said given one state continues;
- (b) a direct current circuit in the form of a loop;
- (c) means responsive to said oscillating signal for generating an uninterrupted direct current flowing around said loop;
- (d) an oscillator for generating a second oscillating electrical signal;
- (e) means responsive to said oscillator for shunting the flow of current in said loop across a given portion of said loop to cause the flow of current in that portion to be interrupted at the frequency of said oscillator;
- (f) means responsive to the flow of current in said portion of said loop for generating a signal having the frequency of said oscillator;
- (g) fail-safe means for actuating a control from an "off" to an "on" condition;
- and
- (h) means responsive to the signal generated by the flow of current in said portion of said loop for actuating said control;
- whereby, non-existence of said one given state or any failure of any component in any element as defined, leaves said control in the "off" condition.
Dependencies are inferred from the claim text.