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US 3,968,489 AGranted
Apparatus for monitoring the operation of heater controllers
AssigneeEastman Kodak Company
InventorsJames J. Richards, Francis A. Russell
Life of this patent
Estimating the term…
Abstract
Circuitry is disclosed that monitors the frequency at which a heater controller applies pulses to a heater to determine if the heater controller is operating properly. If the heater controller fails to generate a pulse in a selected interval, the circuitry generates a signal that activates an alarm and interrupts the operation of a machine that is processing material heated by the heater.
Claims5
In combination:
- a heater;
- temperature sensing means for measuring the temperature of a material heated by said heater;
- a controller responsive to said temperature sensing means for sequentially generating heater signals that periodically activate said heater;
- means actuated by said heater signals for monitoring the rate at which said heater signals are generated, said means comprising:
- illumination means actuated by said heater signals for generating light pulses;
- a photosensor for converting the light pulses into corresponding electrical signals, and
- a timing circuit responsive to each of said electrical signals for establishing the rate of electrical signal generation;
- means responsive to the monitored rate for generating an output signal when said monitored rate is less than a selected rate;
- and
- an alarm responsive to said output signal for signalling the occurrence of improper controller operation.
7 more elements
In combination:
- a heater;
- temperature sensing means for measuring the temperature of a material heated by said heater;
- a controller responsive to said temperature sensing means for periodically generating pulses that are applied to said heater;
- photoelectric detection means for detecting the occurrence of each of said pulses;
- timing means responsive to said photoelectric detection means for generating an interval signal representing the interval separating the occurrence of said pulses;
- a reference signal with a magnitude representing a selected interval;
- comparator means for generating an output signal when the magnitude of said interval signal is greater than the magnitude of said reference signal;
- gating means responsive to said output signal for generating a malfunction signal;
- and
- utilization means responsive to said malfunction signal for signalling the improper operation of said controller.
7 more elements
In apparatus for processing a material, the combination comprising:
- a machine for processing the material;
- a controller for periodically generating electrical pulses;
- a heater responsive to said electrical pulses for heating said material;
- means directly responsive to said pulses for monitoring the frequency of said pulses to which said heater is responsive, said means comprising:
- illumination means responsive to the occurrence of each of said electrical pulses for generating a corresponding light pulse,
- a photosensor for converting the light pulses into corresponding electrical output signals, and
- a timing circuit responsive to said electrical output signals for establishing the frequency of said electrical output signals;
- means for generating an output signal when the monitored frequency is less than a selected frequency;
- and
- means responsive to said output signal for terminating the operation of said machine.
7 more elements
In apparatus for processing a material, the combination comprising:
- a plurality of heaters for heating said material;
- a controller for periodically applying pulses to each of said heaters;
- a machine for processing the heated material;
- a plurality of timing circuits actuated by said pulses for timing the intervals separating the occurrence of pulses applied to each of said heaters;
- a plurality of comparators, each responsive to one of said timing circuits, for generating an output signal when an interval timed by its associated timing circuit exceeds a selected interval;
- gating means responsive to the output signal generated by any one of said comparators for generating a malfunction signal;
- and
- alarm means responsive to said malfunction signal for signalling the occurrence of improper controller operation.
5 more elements
Dependencies are inferred from the claim text.