Abstract: An electromagnetic valve circuit used in a fluid line security device is disclosed. The circuit is adapted to open and close a fuel supply pipe. The circuit includes an attracting circuit and a holding circuit connected to one side of a power source. The attracting circuit including an attracting switch is in parallel with the attraction holding circuit. The attracting switch is closed only when the attraction phase of value opening is to be accomplished. In one modification the series circuit of the attracting switch and the electromagnetic valve circuit is coupled in parallel to a circuit formed by a hazard detecting switch, and a relay switch operating coil. In another modification a time limit current control is connected in series with the valve coil to control the supply of current to the coil for a predetermined time limit.

Abstract: Frying apparatus including a fry pot and a filter system operable during a cleaning cycle for dislodging food particles which cling to the fry pot and for removing food particles suspended in the cooking oil is disclosed. The filter system includes a shower apparatus which discharges jets of cooking oil along the interior side surfaces of the fry pot to dislodge food particles clinging thereto. The cooking oil is drained into a drain pan, strained through a filter and means are provided for pumping the filtered cooking oil back to the fry pot where it is discharged through the shower apparatus. Food particles are continuously separated from the cooking oil as it is conveyed from the fry pot through the filter into the drain pot. In a preferred embodiment, a control circuit is provided for automatically turning off the fry pot heaters when the cooking oil is drained during the filter cycle.

Abstract: A latching relay employing an electro-magnetic relay coil having associated therewith opposite end armatures. This relay coil receives operating power by way of an input contact member. One of the armatures carries a manually operated switch which also includes an end for actuating the closure contact. The opposite armature functions to assist in the manual switching and in its inactive state blocks operation of the primary armature. Another contact is associated with one of the armatures for providing high power transfer.

Abstract: An electromagnetic relay is provided with a high current "boost" coil, a lower current normal operating or "seal" coil and a static, electronic circuit that functions under low voltage conditions to energize the boost coil to retain the relay closed. An additional function of this static, electronic circuit is to energize the boost coil for a time interval on initial power application in order to assist in closing the relay, and this time interval automatically varies in the correct direction with variation in the supply voltage available to the coil so that the lower such available voltage is from its normal value, the longer the boosting time interval. At other times, both coils are energized in series at low current to hold the relay closed. This static, electronic circuit is small enough to be integrally incorporated within the housing of a conventional sealed power relay.

Abstract: Disclosed herein is a direct current motor control circuit adapted for connection to first and second supply terminals of DC power source and to a DC motor connected between the positive and negative terminals of a DC power source, the control circuit including a solenoid including a solenoid coil having one end connected to the first supply terminal and having an opposite end, and having a pair of solenoid contacts connected in series relation with the DC motor between the positive and negative terminals and which close to energize the DC motor when current flows through the solenoid coil.

Abstract: An improved circuit for interfacing between a test desk, a subscriber line and an electronic switching center is disclosed herein. The disclosed improvements allow the relay circuit to operate in response to a predetermined threshold current value while requiring only a minimal current flow and thereby providing the capability to use components lower rated in terms of power consumption.

Abstract: A solenoid drive circuit to enhance the operation of an alternating current solenoid. The circuit supplies alternating current to the solenoid when its plunger is in an extended position and then switches to a direct current when the plunger is in its home position, thereby eliminating any buzzing due to plunger misalignment or other inherent characteristics of the solenoid or associated mechanism and drawing less power than if it was being held in its home position with alternating current voltage. The invention has wide applicability but is disclosed herein in association with the operation of a fail-safe device, particularly a device to prevent fires from starting in a radiant energy fixer of an electrostatic copying machine in the event of a sudden loss of power.

Abstract: The coil of a relay is activated by a DC voltage directly through a primary switch, which voltage is also applied through a diode to charge a capacitor. A transistor biased by the same DC voltage is connected across the charging diode, but poled for conduction in the opposite direction. When the power is removed from the relay coil and the charging diode, the transistor is forward biased and conducts the charge from the capacitor through the relay to keep the relay energized until such time as the capacitor charge equals the transistor bias; then the transistor cuts off and the relay opens immediately. Relay energization is independent of the transistor; if the transistor fails open, the relay is disenergized instantaneously; if the transistor fails shorted, the relay is deenergized when the capacitor voltage drops below the dropout voltage of the relay; therefore, the circuit is fail safe.

Abstract: A control circuit is provided for a contactor which has a pair of contacts and an actuator coil which is energizable under the control of a switch to cause the contacts to close. The control circuit provides a temporary path for energizing the coil and a permanent path through the contacts. The control circuit delays energization of the coil for a preselected time to allow switch contact bounce to cease. The control circuit prevents a reestablishment of the temporary path for preselected time after the contacts close.

Abstract: A protective circuit for an electronic switching amplifier is controlled by an operating switch, the amplifier serving to turn on an electromagnet with timed pulses during its operating interval. The electromagnet may electromagnetically actuate positioning and actuating elements on sewing machines and the like, with the timed pulses. A cutoff voltage limiting circuit is connected on one side between the electromagnet and the switching amplifier. A free-running diode is connected in parallel with the electromagnet through an electronic switch as an additional cutoff voltage limiting circuit. The electronic switch is caused to conduct by the switching amplifier during the operating interval, at least during the decay of the timing pulses. The electronic switch is blocked when the operating interval is terminated by the operating switch. The cutoff voltage limiting circuit is designed to conduct when electronic switch is blocked.

Abstract: A battery is connectable through a mechanical switch to bias a solid state switch and to charge a capacitor. When the mechanical switch is open, the capacitor supplies current to bias the solid state switch. The battery is connected for supplying a trickle electrical current to the capacitor when the mechanical switch is open for maintaining a charge on the capacitor for a substantial period of time without materially discharging the battery.

Abstract: A non-lethal protective system includes a defensive weapon, for example a gas canister, which may be rendered operative by means of actuating a remotely located electrical switch. Operation of the defensive weapon is effected by a solenoid which is controlled by a circuit including a pair of interlock switches which arm a main control switch.

Abstract: Control system for an electromagnet having a movable core, wherein a power winding is provided for moving the core to active position and a holding winding requiring less power maintains the core in active position. A transistor controls the power supply circuit and, when made conductive, energizes a transistor in series with each winding, thus energizing both windings. After a time delay provided by a resistor-condenser circuit, another transistor is energized which causes the transistor in the power winding to become non-conductive, thus de-energizing the power winding. De-energizing the control transistor causes the transistor in the maintenance winding to become non-conductive so that the maintenance winding is de-energized and its energy is dissipated through a Zener diode and a resistor, both in series therewith.

Abstract: A method of, and apparatus for, controlling the startup, the normal operation and the stopping of all spinning positions of an open-end spinning machine provided with an electronic control unit supplied with power via a supply line. Control circuits extend from the electronic control unit to devices which influence the course of the spinning position. In the event of failure of the electronic control unit the normal operation is maintained.

Abstract: A pair of pancake-like coils have a coil axis substantially colinear with one coil mounted to a framework and the other coil mounted on a movable member. The coils are wound such that when electrically energized simultaneously the resulting magnetic fields are in opposition, thereby producing a repelling force therebetween. A spring is disposed between the framework and the movable member to urge the movable member in a sense opposite to the repelling force. A power supply is connected to the coil pair providing for a high initial energy transfer and a lower sustaining energy transfer. A shock absorber is mounted on the framework to arrest the moving member which is set in motion by the repelling force. An armature is attached to the moving member which enters the field of a holding coil as the moving member is displaced by the repelling force. When the holding coil is energized with the armature situated therein, the moving member is held against the spring force.

Abstract: Solenoid has a coil which when energized moves a plunger inwardly through an opening in the housing against an external biasing spring which moves the plunger outwardly when the coil is deenergized. The front end wall of the housing has a plurality of bores disposed radially to the axis of movement of the plunger, each having a ferrous guide sleeve with an open end adjacent the plunger and a loose magnetic steel ball which is freely movable therein toward the plunger when the coil is energized. The plunger has an external groove within which the balls are seated when the plunger is in a fully retracted position. This enables the balls to extend from the open inner ends of the guide sleeves into latching positions holding the solenoid against outward movement. A much smaller electric power input is required in the coil to hold the balls in latched position, and therefore hold the plunger in retracted position, than is required to move the plunger to that position in the first place.

Abstract: A signal is generated indicating a defect in a woven fabric and applied to a counting circuit stopping the loom which starts at a normal operating condition after correction when a normal length of fabric has been made in response to a reset signal.

Abstract: Contactors and housings therefor wherein the contactor is provided with blow-out coils brought into circuit by the arc; arc extinguishers; and fuses in series with the contacts; a closing and holding magnet for operating the contacts; anti-single-phasing operation to open the contacts in response to overload interruption by a fuse; the housings being of modular arrangement to form a uniform control center and being provided with racking means for inserting and removing the contactors with the door closed; and means for protecting the operator including the closing off of access to at least the line bus when the contactor is racked out and disabling the racking mechanism when the contactor contacts are closed.

Abstract: An improved supply circuit for electromagnets. The supply circuit comprises a bridge rectifier, an attracting winding positioned in the diagonal of the bridge rectifier, a holding winding placed on the magnetic circuit of the electromagnet, and an isolating contact which isolates the bridge at the end of the pulling-in course of the movable member of the magnetic circuit. The holding winding being connected in parallel across the system formed by the isolating contact and the bridge rectifier.

Abstract: An interfacing circuit for use in industrial control systems which provide one or more control signals of low power level from integrated semiconductor circuits. The low power level control signals initiate operation of the interfacing circuit to complete a current path from a power source to an electrical load in the control system. Buffer circuits are provided as a part of the interfacing circuit for receiving the lower power level control signals. A reed relay is operated initially by the low power level signals. The relay has a normally open set of contacts which when operated completes the current path from a power source to the electrical load. The interfacing circuit includes a holding current path for the relay. A number of diodes are provided in the interfacing circuit for preventing unwanted current flow in various areas of the circuit under certain circumstances.

Abstract: An electric system normally responsive to radiation over a path traversed by a body of material. An auxiliary radiation source generates a continuous signal through the portion of the circuit monitored for failure. The continuous signal opposes deenergization of the system relay during the period the material blocks normal radiation to the system and while the monitored circuit is operative.