Apparatus for monitoring the operation of heater controllers

Claim 2

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.

Claim 3

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.

Claim 4

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.

Claim 5

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.

Claim 6

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.

Claim 7

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.

Claim 8

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.

Claim 9

The apparatus of claim 4, further comprising: a container for storing the heated material; an extruder for conveying said heated material from said container to said machine; and a control circuit responsive to said malfunction signal for terminating the operation of said extruder.