Texas Instruments Corporation

Richard L Jenne

Sepideh H Nott

Carleton M Cobb, Iii

Edward M Gonsalves

Hans G Hirsbrunner

Leo Marcoux

Lawrence E Cooper

Steven K Sullivan

Stanley J Nacewicz

Gennady Baskin

Thomas E Evans

Alfred Raulino

Richard C Ellis

A telephone line overcurrent protector adapted to be mounted on a circuit board is shown having a cup shaped housing in which a PTC element is placed with leads extending out of the housing through apertures in a bottom cover. The bottom cover is formed in one embodiment with a frangible diaphragm to provide guided pressure release upon catastrophic failure of the PTC element, in another embodiment with open apertures in the bottom cover and in yet another embodiment with means to mount a snap out member closing an aperture in the bottom cover, both for the same purpose of providing guided pressure release.

Solid state electronic protector with pressure release

A split phase electric motor starter and protector are shown having a housing which receives a PTC starter switch and a motor protector and provides various wiring options for connecting the PTC switch and, if desired, a capacitor to a motor depending upon the particular requirements of an application. The housing optionally accommodates a capacitor support bracket.

Mounting apparatus for electrical motor control components

A motor winding system having a main winding and a start winding circuit with a start winding and a PTC resistor in series therewith wherein the resistor is electrically removed from the circuit at a predetermined time after motor starting and remains in this state until motor shut off. The start winding circuit also includes a bimetallic switch in series with the resistor and a series circuit of a capacitor and an electromagnet in parallel with the resistor and switch. At motor start up, current from the main power source is applied across the main winding and the start winding circuit heats up the resistor and causes an increase in the resistance thereof. Also, current through the switch and PTC heat causes the bimetallic element to snap or move when it has reached a predetermined temperature to open the start winding circuit. Meanwhile, low current passes through the capacitor and electromagnet winding, energizing the electromagnet and causing the bimetallic element to be attracted and latched to the electromagnet after predetermined movement.

PSC motor start system

A circuit breaker has two thin flat terminals embedded in an electrically insulating housing exposing respective broad flat sides of the terminals in spaced side-by-side relation to each other in a housing chamber. The circuit breaker has a thermostat metal member secured at one end to one exposed side of one terminal to mount the member extending along a chamber wall and has a contact at its opposite end to engage and disengage the other terminal to close and open a circuit in response to a selected current in the circuit. The contact comprises a material which erodes during repeated cycling of the circuit breaker. The thermostat metal member has a portion of reduced cross-sectional area adapted to burn out and separate the member into two sections to open the circuit if the contact welds or sticks to the other terminal. A stop on the housing intercepts movement of one of the member sections after burn out to avoid shorting of the circuit. An abutment on the housing prevents reclosing of the circuit after the contact has eroded to a selected extent. In one embodiment, an electrical resistance heater of positive coefficient of resistivity having an improved electrical wire insulation is wound on the thermostat metal member and retains the circuit in an effective open circuit condition until the heater circuit is separately interrupted to reset the breaker.

Circuit breaker

A circuit breaker device has a chamber in which is disposed a single break contact system using low contact resistance material mounted on movable and stationary supports arranged in a loop configuration in order to direct arcs between the contacts through an arc chute into a remote portion of the chamber. A push-button is connected through a kinematic linkage which transfers motion using minimal frictional engagement to a movable contact to bring the movable contact into and out of engagement with a stationary contact and to latch the contacts in engagement during normal operation. A cantilevered current carrying bimetal transfers motion caused by I R heating of the bimetal to an ambient compensating bimetal connected to the latch mechanism. The kinematic linkage includes a latch surface which engages a rollable cylindrical reaction surface of the latch mechanism to cause the movable contact to come into engagement with the stationary contact upon depression of the push-button. Upon overload, the latch mechanism is displaced with the latch surface moving away from the reaction surface allowing return springs to return the push-button to its unactuated position and separate the contacts.

Miniature circuit breaker with improved longevity

A circuit breaker device has a chamber in which is disposed a single break contact system using low contact resistance material mounted on movable and stationary supports arranged in a loop configuration in order to direct arcs between the contacts through an arc chute into a remote portion of the chamber. A push-button is connected through a kinematic linkage which transfers motion using minimal frictional engagement to a movable contact to bring the movable contact into and out of engagement with a stationary contact and to latch the contacts in engagement during normal operation. A cantilevered current carrying bimetal transfers motion caused by I2R heating of the bimetal to an ambient compensating bimetal connected to the latch mechanism. The kinematic linkage includes a latch surface which engages a rollable cylindrical reaction surface of the latch mechanism to cause the movable contact to come into engagement with the stationary contact upon depression of the push-button. Upon overload, the latch mechanism is displaced with the latch surface moving away from the reaction surface allowing return springs to return the push-button to its unactuated position and separate the contacts.

A circuit breaker device has a chamber in which is disposed a single break contact system using low contact resistance material mounted on movable and stationary supports arranged in a loop configuration in order to direct arcs between the contacts through an arc chute into a remote portion of the chamber. A push-button is connected through a kinematic linkage which transfers motion using minimal frictional engagement to a movable contact to bring the movable contact into and out of engagement with a stationary contact and to latch the contacts in engagement during normal operation. A cantilevered current carrying bimetal transfers motion caused by I.sup.2 R heating of the bimetal to an ambient compensating bimetal connected to the latch mechanism. The kinematic linkage includes a latch surface which engages a rollable cylindrical reaction surface of the latch mechanism to cause the movable contact to come into engagement with the stationary contact upon depression of the push-button. Upon overload, the latch mechanism is displaced with the latch surface moving away from the reaction surface allowing return springs to return the push-button to its unactuated position and separate the contacts.

A control for modulating the duty cycle of diesel engine glow plugs has two heat sensitive, normally closed switches each thermally coupled to a respective positive temperature coefficient (PTC) of resistivity heater in turn thermally coupled to and mounted on a common heat sink. The heat sensitive switches are serially connected to each other, to an ignition switch and to a glow plug relay. The PTC heaters are connected to a point between the heat sensitive switches and the relay and to ground. A third PTC heater is mounted on the heat sink intermediate the first and second heaters and thermally coupled to the heat sink. The third heater is connected to an alternator and serves to cut off power to the glow plugs after a selected after glow stage. The two heat sensitive switches can be selected to open at approximately the same temperature for a random operating mode or at slightly different temperatures for a sequential operating mode. The random operating mode is a redundant high reliability operating mode whereas the sequential operating mode, using slightly different temperatures allows one switch to control the cycling and the second to be a back up safety control. In one preferred embodiment a 'wait' lamp is connected between the ignition switch and a double pole relay used to latch the lamp in the deenergized state when the first 'off' time of the heat sensitive switches occurs. In a second embodiment the 'wait' lamp is connected between the alternator and the coil of the glow plug relay with a diode serially connected to the lamp to preclude alternator current from energizing the lamp.

Glow plug duty cycle modulating apparatus

A compact, low cost, snap-acting thermostatic switch which can be automatically assembled comprising a single member housing, an unrestrained snap-acting disc, a stationary contact means and a movable contact means with a transfer means attached thereto in which calibration in assembled form can be performed as a single final operation.

Thermostatic switch and method of assembly

A system for monitoring usage of seat belt means in a motor vehicle includes electrically operable visual signaling means and electrically operable audible signaling means. A first switch is operable in response to initiation of motor vehicle operation for connecting the signaling means to an electrical power supply in the vehicle. An additional switch is operable in response to fastening of the vehicle seat belt means for preventing operation of the audible signaling means. An electrical resistor of positive temperature coefficient of resistivity is arranged to be heated to a selected temperature with a selected time delay after initiation of motor vehicle operation for preferably terminating operation of both signaling means after such time delay even if the vehicle seat belt means are not fastened.

Automotive seat belt monitoring system

A system for monitoring usage of seat belt means in a motor vehicle includes electrically operable visual signaling means and electrically operable audible signaling means. A first switch is operable in response to initiation of motor vehicle operation for connecting the signaling means to an electrical power supply in the vehicle. An additional switch is operable in response to fastening of the vehicle seat belt means for preventing operation of the audible signaling means when the seat belt means are properly fastened. A pair of first electrical resistors of positive temperature coefficient of resistivity which are adapted to display a sharp increase in resistivity when heated to predetermined operating temperatures are arranged in series between the vehicle power supply and the visual and audible signaling means respectively for terminating operation of said signaling means individually when said first resistors are heated to said operating temperatures. A third electrical resistor of positive temperature coefficient of resistivity which displays a sharp increase in resistivity when heated to a predetermined operating temperature is arranged to be connected to said vehicle power supply on initiation of vehicle operation and is disposed in selected heat-transfer relation to said first resistors for heating said first resistors to their operating temperatures with a selected time delay after initiation of motor vehicle operation, thereby to terminate operation of said signaling means after said time delay even if said vehicle seat belt means have not been properly fastened. A control device particularly adapted for use in such seat belt monitoring systems includes a casing having a cavity and having a plurality of slots extending into the casing cavity. Three terminals are disposed in respective casing slots to dispose one end of each terminal within said cavity. The pair of first resistor elements are disposed in the casing cavity to electrically engage respective terminals and the second resistor is disposed in the cavity in heat-transfer relation to the first resistors to electrically engage each of the first resistors and to electrically engage a third terminal. A fourth terminal disposed in a fourth casing slot also electrically engages the second resistor and a cover secured to the casing retains the resistors and terminals in assembled relation. This control device is therefore adapted to be conveniently combined with existing automotive switch means to economically provide seat belt monitoring systems as above-described.

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Attleboro, MA, United States of America

Richard L Jenne