Abstract: A flying optical head assembly for a magneto-optical data storage device includes a slider body mounting an optical element having a narrowed optical aperture extending through a location of the slider body, a recessed region surrounding the location passing the optical aperture, a magnetic pole sheet layer for heat dissipation and reduced magnetic reluctance formed in the recessed region and having an insulation layer and an opening for the optical aperture, and a magnetic bias coil formed on the insulation layer and surrounding the narrowed optical aperture. When formed of electrically conductive material, the sheet layer includes at least one radial slot for preventing a single turn short circuit in direct proximity to the coil. Multiple slots are preferred for bonding and to reduce eddy currents.

Abstract: A lighted escutcheon plate for power distribution equipment includes an escutcheon plate in electrical communication with a power distribution circuit; and a plurality of LED bulbs, generally green or alternatively red, mounted on the escutcheon plate, so as to provide a visual indication of an open circuit status by lighting when the power distribution circuit is opened. The plate also includes a plurality of LED bulbs, generally red or alternatively green, mounted on the escutcheon plate, so as to provide a visual indication of a close circuit status by lighting when the power distribution circuit is closed. For tripped circuit conditions the plate includes a plurality of LED bulbs, generally yellow or amber, mounted on the escutcheon plate, so as to provide a visual indication of a trip circuit status by lighting when the power distribution circuit is tripped.

Abstract: This invention provides a residual current detector comprising a trip circuit; a magnetic lock assembly including a solenoid that operates in response to a signal from the trip circuit, causing movement of an operating member, with the magnetic lock further including a reset mechanism for resetting the residual current detector following a trip operation; and means for preventing reset of the magnetic lock by restraining movement of the solenoid when the trip circuit is disabled. In the preferred embodiment, a plunger assembly is mounted adjacent to the solenoid of the magnetic lock assembly and fusible link is connected in series with the trip circuit and mounted to prevent movement of a plunger in the plunger assembly. When the trip circuit is subjected to excessive current, the fusible link will melt, thereby permitting the plunger to interfere with movement of the armature of the solenoid. This prevents rest of the magnetic lock assembly.

Abstract: A solid state control system for controlling activation signals to circuit breaker electro-mechanical close coils is disclosed. The system employs a novel arrangement of a silicon controlled rectifier (SCR) and other electronic components, such as a FET, to provide "anti-pump." The system locks out continuous close signals until after the close signal has been removed and then reapplied.

Abstract: A microwave oven includes a housing formed by relatively separable first and second panels. Electric switches are mounted on the first panel and are connected to respective wires of the power cord by the oven. Each switch includes a movable contact which moves away from a respective fixed contact when the panels are separated from one another, in order to automatically cut off the supply of electric power to the oven in the event that the worker forgets to unplug the power cord. When the panels are reconnected, the switches are automatically closed. Such automatic closing can be caused by magnetic force produced by magnets carried by the second panel. Alternatively, the automatic closing can be caused by screws carried by the second housing and which physically push respective movable contacts against their associated fixed contacts.

Abstract: A baler feed gate safety sequencing circuit which prevents successive operation of a compactor baler with the feed gate in the open position. The circuit requires the raising and lowering of the feed gate after each compaction cycle for operation of the baler ram, even if the gate limiting switch is rigged to provide an indication that the feed gate is closed when in reality it is open.

Abstract: A counter indicator for circuit breakers maintaining a running count of the number of times that a circuit breaker has been tripped and providing a visual indication of a tripped condition. The counter indicator employs time delay circuitry so as to allow the circuit breaker to be switched manually for purposes of testing without registering a tripped condition. A two stage binary coded decimal counter visually displays the amount of counts that the breaker has been tripped or alternatively when a switch handle has been placed in an intermediate position. The device is powered by an independent battery source providing a continuous power supply to maintain memory and power to a visual display only upon detection of a tripped circuit.

Abstract: An integrated circuit breaker having several accessory functions along with automatic overcurrent protection, allows selection between the various accessory functions in different combinations. Separate switches are arranged on the circuit breaker to allow factory as well as field selection of the accessory function combinations.

Abstract: An improved ground fault circuit interrupter (GFCI) device requires manual setting following initial connection to an AC power source or termination of a power source interruption. The improved GFCI device utilizes a controlled switching device which is responsive to a load power signal for allowing the relay contact sets of the GFCI device to be closed only when power is being made available at the output or load terminals. The controlled switching device preferably comprises an opto-isolator or other type of switching device which provides isolation between the GFCI input and output terminals when the relay contact sets are open. The improved GFCI device may be incorporated into portable units, such as plug-in or line cord units, for use with unprotected AC receptacles.

Abstract: A ground fault interruptor circuit interrupts the flow of current to a pair of lines extending between a source of power and a load. The ground fault interruptor circuit includes a circuit breaker comprising a normally open switch located in one or both of the lines, a relay circuit for selectively closing the normally open switch, an electronic latch circuit operable in first and second bi-stable states and a fault sensing circuit for sensing the presence of a fault condition in at least one of the lines. The electronic latch circuit causes the relay circuit to close the normally open switch and maintain the normally open switch in its closed position when the electronic latch circuit is in the first bi-stable state. The electronic latch circuit also causes the relay circuit to permit the normally open switch to return to its normally open condition when the latch circuit is in its second bi-stable state.

Abstract: A circuit breaker comprises a static switch electrically connected in series with a disconnecting switch having an operating mechanism with a handle to close and open a system of main contacts. A voltage sensor ocmprises an electromagnet with a moving core capable of occupying an active locking position and an inactive unlocking position of the mechanism, respectively in the on state and in the off state of the switch. Opening of the disconnecting switch is inhibited if voltage is present on the output terminals.

Abstract: A multiple outlet receptacle has a molded insulating body which includes multiple groups of internal contact elements disposed in the body and defining multiple electrical outlets adapted for receiving multiple outlet plugs. The receptacle also has a circuit breaker mechanism and a continuity switch mechanism mounted in the body and connected in series with one another and with an electrical power cord and each of the multiple electrical outlets for respectively protecting external electrical circuits plugged into the multiple electrical outlets and switching on and off external electrical circuits plugged into the multiple electrical outlets.

Abstract: A power controller comprises a manually-on circuit breaker having an electrically-actuatable trip coil which enables the circuit breaker to be tripped-off electrically. The circuit breaker is connected to a voltage source and provides operating voltage to a power outlet. A line voltage monitor provides a voltage indication to a logic control circuit when operating voltage moves outside a predetermined range established by setting upper and lower operating voltage limits. In response to receiving such a voltage indication, the logic control circuit deenergizes a relay, thereby connecting a charged capacitor to the tripping coil of the circuit breaker to cause the breaker to be tripped-off even when the voltage to the circuit breaker drops to zero volts. Other signals provided to the control logic circuit also cause the deenergizing of the relay controlling the circuit breaker tripping capacitor.

Abstract: A steam iron having a protection circuit which is located in a detachable back cover. The back cover can be detached from the iron to allow substitution of an inoperative protection circuit.

Abstract: Fault currents in the phases of a three-phase supply are detected by transformers 28 in respective phase links 14 and are counted by associated circuits 24 when any one of the circuits 24 reaches a predetermined count level, or when there is a fault condition, a low VA trip coil 42 is energized so as to release latches which hold the phase links 14 in their operative positions and thereby cause all three links 14 to drop out together.

Abstract: A remotely controlled circuit breaker or switch comprises two breaking poles adjoining a remote control unit with an electromagnet, and a toggle for manual operation of the contacts. The remote control unit comprises a selector switch for switching into the electronic circuit a position detector of breaker contacts, four connection terminals, and an electronic power supply circuit for an electromagnet. Two of the input terminals TL (inpulse relay mode) and CT (contactor mode in the active position of the selector switch), are accessible simultaneously with the existence of a priority code between the two controls and of a refresh function of the statuses of the electronic circuit. The latter allows forced manual operation by means of the toggle.

Abstract: An electrical safety disconnect device inserted in overhead power wires to prevent live broken wires from contacting the ground or persons in their vicinity. The device takes the form of a male-female plug combination that automatically separates when the wire experiences a predetermined force generally less than that required to break the wire itself. A band encircles both the male and female components to hold them together and maintain the electrical connection. This band breaks when a predetermined stress pulls on the wires to allow the male and female portions to separate. The device sits on the wire near to the pole closer to the source of electricity. Upon separating, as in a storm for example, the "live" end of the wire hangs above the ground where it cannot contact people or other objects. Placing the female component on this portion of the wire provides additional protection to the environs.

Abstract: A time delay undervoltage release for an electric circuit breaker causes the circuit breaker to trip when the control voltage drops below an acceptable level and prevents the breaker from being closed until the control voltage rises to a predetermined level. When the control voltage drops below an acceptable level, the undervoltage release energizes a trip solenoid to trip the breaker. A variable delay is interposed between the control voltage dropping below the acceptable level and the trip solenoid being energized. At the same time the trip solenoid is energized, an inhibit solenoid is deenergized to block the operation of the push-to-close button. When the control voltage increases to a predetermined level, the inhibit solenoid is energized, allowing the push-to-close button to be manually operated and the breaker returned to service.

Abstract: A remotely controlled circuit control device has first and second load contact assemblies movable into circuit engagement and circuit disengagement positions relative to one another in which one load contact assembly is operatively connected to a solenoid so that alternate forward strokes of the solenoid moves the one load contact assembly between reset and tripped positions through a push-push mechanism having an indexing portion and a latching portion. An overload mechanism cooperates with the latch portion to cause the load contact assemblies to move to the circuit disengaged position upon occurrence of a fault condition. The second load contact assembly includes pivotably mounted contact members which are linked to the first load contact assembly in such a way that circuit engagement during solenoid energization is precluded.

Abstract: This disclosure relates to methods and apparatus for providing in a tool, appliance, or other electrically operated device the safety feature of requiring that the trigger or ON-OFF switch be in or returned to the OFF position before the tool will respond to placing the trigger or ON-OFF switch in the ON position.

Abstract: A remotely controlled circuit control device has first and second load contact assemblies movable into circuit engagement and circuit disengagement positions relative to one another in which one load contact assembly is operatively connected to a solenoid so that alternate forward strokes of the solenoid moves the one load contact assembly between reset and tripped positions through a push-push mechanism having an indexing portion and a latching portion. An overload mechanism cooperates with the latch portion to cause the load contact assemblies to move to the circuit disengaged position upon occurrence of a fault condition. The second load contact assembly includes pivotably mounted contact members which are linked to the first load contact assembly in such a way that circuit engagement during solenoid energization is precluded.

Abstract: A picket or zig-zag type heater for use in high temperature furnaces, such as are used for crystal growing for example, is constructed from a plurality of like graphite cylindrical shell segments assembled into a cylindrical shell having uniform resistance heating characteristics by graphite connector elements which also function to couple the electric current source to the heater.

Abstract: An A.C. overload current sensing, remote power controller of minimum size and weight and integral construction. Current rate sensing wound toroids are used that are small enough to fit around the line terminal studs without having to enlarge the prior insulator space available therein. The electronic overload current detecting and tripping control circuit is replaced by a pair of modules, detector and control modules, having improved performance and a shape and size such that they fit within the relay housing alongside its operating magnet. The detector module has integrator means for converting current rate of change signals into current magnitude indicative signals thereby enabling use therewith of rate sensing wound toroids of about one-tenth the size of equivalent current transformer wound toroids.

Abstract: A computer power/temperature protector is provided. A control and disconnect circuit is responsive to a power interruption to disconnect power from a computer to which the protector unit is connected in-line, and thereafter responsive to a reset signal to connect power to the computer. A power interruption is obtained automatically when a voltage failure occurs on the power cable to the computer. A thermostatic switch also automatically interrupts power when the ambient temperature of the room in which the computer or other load is located exceeds an adjustable pre-set level. A power emergency disconnect switch is provided for manually interrupting power. Furthermore, the present invention provides at least one varistor for shunting transient voltages. The varistors are automatically connected to the power lines of the cable when the apparatus is manually reset to supply power to the computer.

Abstract: A protection circuit suitable for use with electronic test equipment contains a switch which is open circuited if an overload condition is detected. The opening of the switch isolates the overload detector from the applied overload thereby allowing the detector to have a relatively low power handling capability. If the switch is manually closed whilst the overload condition persists the switch is automatically re-opened within a short predetermined time.

Abstract: A reset lockout addition to an A.C. overload current sensing, remote power controller of minimum size and weight and integral construction. Current rate sensing wound toroids are used that are small enough to fit around the line terminal studs without having to enlarge prior insulator space available therein. The electronic overload current detecting and tripping control circuit, is replaced by a pair of modules, detector and control modules, having improved performance and a shape and size such that they fit within the relay housing alongside its operating magnet. The detector module has integrator means for converting current rate of change signals into magnitude indicative signals thereby enabling use therewith of rate sensing wound toroids of about one-tenth the size of equivalent current transformer wound toroids.

Abstract: The circuit breaker is taught with an anti-pumping control circuit. If the circuit breaker closes on a fault and quickly reopens without the closing switch being either mechanically or electrically released in the interim, reclosure of the circuit breaker either by an automatic reclosure or by the mere fact that the closing switch remains closed will be prevented until the closing switch is once again opened. In addition, if the closing switch is actuated prior to power being applied to the circuit breaker control system, the circuit breaker will not close when power is applied. The closing spring will be charged, however, for a subsequent circuit breaker closing after release and reactuation of the closing switch.

Abstract: A television system specially constructed for rental use. Such a television system generally includes a key actuated switching system. When the key actuated system is turned on, it enables the televsion to be normally operated. Often, however, there is a desire to enable the user to actuate the television without having to wait for the operator who has the key for the key actuating system. For this purpose, the television system includes an override switching system which enables the television to be operated without the necessity of turning on the key actuating switch. When the override switch is actuated, an indicating signal is generated so as to indicate that the television is in use.

Abstract: Control apparatus is provided for a contactor which has a coil and at least one pair of contacts movable from an open position to a closed position in response to energizing the coil. The control apparatus includes apparatus for temporarily and permanently energizing the coil and switching apparatus for controllably energizing the coil.

Abstract: A motor control circuit for preventing automatic restarting of an electric motor following an interruption of electric current flow therethrough. An electric motor incorporates winding means and a series automatic reset thermal overload protector. Current flow to the motor is normally controlled by current supply switch means in series with the motor across electric power input terminals. A first relay device is switched by external actuation of a normally open start switch to switch the current supply switch means to its conductive state for starting the motor. A second relay device connected across a pair of motor terminals is energizable in response to current flow through the motor. A restart prevention switch connects in series with the current supply switch and motor across the electric power terminals.

Abstract: A ground fault circuit interrupter (GFI) in which a load circuit is energized through a normally closed magnetically latchable circuit breaker. When no fault exists that is of sufficient magnitude to actuate the GFI, the latching coil of the circuit breaker is ineffective, whereby the circuit breaker remains closed. The coil is connected to the amplified DC output of a ground fault sensing circuit and is energized in a certain sense to open the circuit breaker upon the occurrence of a fault, the circuit breaker then being magnetically latched open. A capacitor is continuously DC charged in a certain sense by the AC supply line through a rectifier. To reset the circuit breaker the capacitor is selectively connected across the coil to discharge a pulse of a sufficient magnitude in a proper sense to reversely energize the coil enough to release the magnetic latch and allow the circuit breaker to reclose. The GFI is tested by closing a circuit that simulates a fault of the low magnitude which is to be sensed.

Abstract: A self-powered solid state overload relay having current transformers energized by current to a motor to be protected. The transformer has secondary windings connected through diodes to charge a capacitor in a circuit which senses the magnitude of motor current and capacitors in a trip-reset circuit which causes the circuit to be interrupted when the motor current exceeds a pre-programmed value. The diodes in capacitor charging circuits are poled so that the capacitor in the sensing circuit and the capacitor trip-reset circuit are charged by opposite polarity rectified half wave current pulses.

Abstract: Apparatus for the prevention of undesirable and possibly hazardous automatic application of power to a load in the event of an outage from a power source and a subsequent re-application of power therefrom. Described is a thyristor type of circuit interrupter coupled into a control circuit which is operative to control the operation of phase-controlled SCR circuit which is cyclically operative to couple power from an AC power source to a load device such as a DC motor. In the preferred embodiment, an SCR circuit interrupter is coupled into the DC supply circuit of a control circuit comprising, inter alia, a pulse generator which provides trigger pulses which are applied to a pair of silicon controlled rectifiers in the phase-controlled SCR circuit.A two-pole, two-position switch is adapted in one (STOP) position to couple the AC power source to the SCR circuit interrupter which includes means for being latched, i.e.

Abstract: A bistable magnetic switch circuit includes one terminal coupled to a source of direct current voltage, a contact coupled to the other terminal of the bistable switch circuit and an armature controlled by the bistable switch circuit to make and break contact with the contact, the bistable switch circuit being energized at a given trip-rated current. A transistor has its collector coupled to the other terminal of the bistable switch circuit, its emitter coupled to a utilizing load and its base coupled to the armature remote from the contact, the transistor being rendered non-conductive when the bistable switch circuit is energized to provide the desired overcurrent protection. A reset switch is coupled between the other terminal of the bistable switch circuit and ground potential to reset the bistable switch to prepare the bistable switch circuit to protect against a continuing or a new overcurrent condition.