Electronic temperature control system

Claim 2

In an electrical temperature control system for detecting and regulating the temperature of a medium with respect to a reference temperature, said system including means for emitting a continuous error voltage corresponding to the temperature difference between said reference and said medium, the improvement comprising, in combination therewith: a. redundant switching means for controlling through selected switches thereof, when actuated, the current flow to said medium, and b. control means responsive to predetermined magnitudes of variation in said error voltage to actuate selected switches of said redundant switching means and operate said actuated switch to control the current flow to said medium and regulate the temperature thereof with respect to said reference temperature.

Claim 3

Apparatus as claimed in claim 1, wherein the redundant switching means includes: a. first switching means for controlling, when actuated, current flow to said medium and regulating the temperature thereof with respect to said predetermined reference temperature, said first switching means having a control terminal connecting to said control means; b. second switching means, activated in response to a first magnitude of variation in said error voltage and connected in parallel with said first switching means for controlling, when actuated, current flow to said medium and regulating the temperature thereof with respect to said predetermined reference temperature, said second switching means having a control terminal connecting to said control means; and c. interchanging means connected in series with said first switching means and said second switching means for selectively deactuating, when eNergized, said first switching means and actuating said second switching means, said interchanging means having an energizing terminal connecting to said control means.

Claim 4

first temperature variation detector means to receive said continuous error voltage and emit logical signals responsive to a first predetermined magnitude of variation between the temperature of said medium and said reference temperature;

Claim 5

first temperature variation detector means to receive said continuous error voltage and emit logical signals responsive to a first predetermined magnitude of variation between the temperature of said medium and said reference temperature;

Claim 6

second temperature variation detector means to receive said continuous error voltage and emit logical signals responsive to a second predetermined magnitude of variation between the temperature of said medium and said reference temperature;

Claim 7

second temperature variation detector means to receive said continuous error voltage and emit logical signals responsive to a second predetermined magnitude of variation between the temperature of said medium and said reference temperature;

Claim 8

Apparatus as claimed in claim 2, wherein: the interchanging means is an electrical relay having two trip circuits and one energizing circuit, one of said trip circuits normally closed and the other of said trip circuits normally open when said relay is deenergized, said normally closed trip circuit connected in series with said first switching means and said normally open trip circuit connected in series with said second switching means, the energizing circuit connecting to said control means.

Claim 9

Apparatus as claimed in claim 2, wherein the control means includes: a. signal converter means to receive said continuous error voltage and emit in response thereto first logical signals, which signals correspond to variations between the temperature of said medium and said reference temperature; b. temperature variation detector means to receive also said continuous error voltage and emit in response thereto second logical signals, which second signals correspond to a first predetermined magnitude of variation between the temperature of said medium and said reference temperature; and c. a logic circuit network responsive to said first logical signals emitted by said signal converter means to operate said first switching means to control current flow to said medium and regulate the temperature thereof with respect to said reference temperature, said logic circuit network further responsive to said second logical signals emitted by said temperature variation detector means to energize said interchanging means, deactuating said first switching means and actuating said second switching means, and operate said second switching means in response to said first logical signals to control current flow to the medium and regulate the temperature thereof relative to said reference temperature.

Claim 10

logic circuit means responsive to said logical signals emitted by said signal converter means to operate said first switching means to control current flow to said medium and regulate the temperature thereof with respect to said reference temperature, said logic circuit means further responsive to said signals emitted by said first temperature variation detector means to energize said first interchanging means, deactuate said first switching means and actuate said second switching means for operation of said second switching means by said logic circuit means responsive to said logical signals emitted by said signal converter means to control current flow to said medium and regulate the temperature thereof with respect to said reference temperature, said logic circuit means further responsive to said signals emitted by said second temperature variation detector means to selectively energize said second interchanging means and remove all current from said medium to regulate the temperature thereof between said second magnitude of variation therefrom and said first magnitude of variation with respect to said reference temperature.

Claim 11

logic circuit means responsive to said logical signals emitted by said signal converter means to operate said first switching means to control current flow to said medium and regulate the temperature thereof with respect to said reference temperature, said logic circuit means further responsive to said signals emitted by said first temperature variation detector means to energize said first interchanging means, deactuate said first switching means and actuate said second switching means for operation of said second switching means by said logic circuit means responsive to said logical signals emitted by said signal converter means to control current flow to said medium and regulate the temperature thereof with respect to said reference temperature, said logic circuit means further responsive to said signals emitted by said second temperature variation detector means to selectively energize said second interchanging means and remove all current from said medium to regulate the temperature thereof between said second magnitude of variation therefrom and said first magnitude of variation with respect to said reference temperature.

Claim 12

Apparatus as claimed in claim 4, wherein the logic circuit network includes: a. first logic circuit means having an output and two inputs, said inputs comprising a signal transmitting input and a logical enabling input, said output connected to the control terminal of said first switching means and said signal transmitting input receiving the first logical signals emitted by said signal converter means to operate, when said first logic circuit means is enabled, said first switching means to control current flow to said medium and regulate the temperature thereof with respect to said reference temperature; b. second logic circuit means having an output and two inputs, said inputs comprising a signal transmitting input and a logical enabling input, said output connected to the control terminal of said first switching means and said signal transmitting input receiving the first logical signals emitted by said signal converter means to operate, when enabled, said second switching means to control current flow to said medium and regulate the temperature thereof with respect to said reference temperature; c. third logic circuit means having an output connected to the control terminal of said interchanging means for energizing, when enabled, said interchanging means to deactuate said first switching means and actuate said second switching means, said third logic circuit means having a logical enabling input to receive a logical enabling signal to enable and disenable said third logical circuit means responsive thereto; and d. an enabling means having two outputs selectively connected to the logical enabling inputs of said first, second and third logical circuit means and one input receiving the second logical signals emitted by said temperature variation detector means, said enabling means first enabling said first logic circuit means and disenabling said second and third logic circuit means and responsive to said second logical signals disenabling said first logic circuit means and enabling said second and third logic circuit means.

Claim 13

Apparatus as claimed in claim 5, wherein the enabling means is a bi-stable multivibrator.

Claim 14

Apparatus as claimed in claim 4, wherein the control means further includes: a. a second temperature variation detection means to receive said continuous error voltage and emit in response thereto third logical signals, which third logical signals correspond to a second predetermined magnitude of variation between the temperature of said medium and said reference temperature; b. a second interchanging means connected in series with said redundant switching means to deactuate, when energized, all of said switching means of said redundant switching means and remove the current from said medium, said second interchanging means having an energizing terminal connecting to said control means; and c. logic circuit means connected to said energizing terminal and responsive to said logical signals emitted by said second temperature variation detection means to energize said second interchanging means and remove all current from said medium.

Claim 15

An electrical temperature control system for detecting and regulating the temperature of a medium with respect to a reference temperature, said system including bridge circuit means for detecting the temperature of said medium and setting said reference temperature, said bridge circuit means having means for emitting a continuous error voltage corresponding to the difference between the temperature of said medium and said reference temperature, said control system comprising in combination: a. first switch means for controlling, when actuated, current flow to said medium, said first switch means having a control terminal; b. second switch means connected in parallel with said first switch means for controlling, when actuated, current flow to said medium, said second switch means having a control terminal; c. first interchanging means connected in series with said first and said second switch means for alternatively activating one of said switching means and deactivating the other, said interchanging c. second interchanging means in series with all of said switch means for removing, when energized, current flow to said medium, said second interchanging means having a control terminal; e. a control circuit coupled to the control terminals of said first and second switching means and said first and second interchanging means, said control circuit comprising:

Claim 16

An electrical temperature control system for detecting and regulating the temperature of a medium with respect to a reference temperature, said system including bridge circuit means for detecting the temperature of said medium and setting said reference temperature, said bridge circuit means having means for emitting a continuous error voltage corresponding to the difference between the temperature of said medium and said reference temperature, said control system comprising in combination: a. first switch means for controlling, when actuated, current flow to said medium, said first switch means having a control terminal; b. second switch means connected in parallel with said first switch means for controlling, when actuated, current flow to said medium, said second switch means having a control terminal; c. first interchanging means connected in series with said first and said second switch means for alternatively activating one of said switching means and deactivating the other, said interchanging c. second interchanging means in series with all of said switch means for removing, when energized, current flow to said medium, said second interchanging means having a control terminal; e. a control circuit coupled to the control terminals of said first and second switching means and said first and second interchanging means, said control circuit comprising: