Abstract: An air ionizer comprises an ion emission wire and a metallic reflecting shield partially surrounding it, the wire and the shield being connected to a high voltage source. The shield is insulated from ground and its two edges define therebetween a discharge region for the emitted ions. The reflecting polarity of the wire and reflecting shield potentials are the same. The high voltage potential at the shield is at least 3000 V, preferably 5000-10,000 V and does not exceed that at the wire. The potential of the high voltage source to which the shield is connected is at least equal to the potential prevailing at the shield edges due to the electrical field generated by the electrical charge at the wire in the absence of a reflecting shield.

Abstract: Method and apparatus for generating particles having the characteristics and mobility of free electrons. The particles may be dispersed into the environment around the apparatus without circulating air through the apparatus. A relatively high alternating voltage is applied between alternate spaced electrically conductive plates covered with a dielectric material which has high coefficients of secondary electron emission and sufficient dielectric strength to withstand the generation of a cold glow discharge or plasma between facing layers of the material.

Abstract: An apparatus for detecting relative movement between two objects which is illustrated in the preferred embodiment as a vehicle road speed signal source including a reed switch oscillator for generating an output signal having a frequency and a magnitude proportional to the road speed of an associated vehicle. Current flows through a biasing coil proximate the reed switch to generate a magnetic field which is slightly less than the field required to close the switch contacts. A permanent magnet means attached to the drive shaft of the vehicle generates a magnetic field which aids the biasing coil magnetic field to close the reed switch contacts. A transistor responds to the closing of the reed switch contacts to turn off the current to the biasing coil which allows the reed switch contacts to open.

Abstract: An electrical contactor device includes a solid state arc suppression circuit connected in parallel with main relay contacts. Auxiliary contacts provide gating signals to the arc suppression circuit prior to, during and shortly after the main contacts open. Protection contacts connected in series with the arc suppression circuit are part of a relay which is actuated by additional auxiliary contacts of the main relay. The protection contacts prevent the arc suppression circuit from operating during initial closure of the main contacts thereby allowing the contactor device to be used in those applications where a high in-rush current is expected. A delay circuit holds the protection circuit relay contacts closed after the main relay contacts open to permit operation of the arc suppression circuit; the relay contacts thereafter open to isolate the arc suppression circuit and thereby to prevent any leakage current from flowing therethrough and to prevent any false triggering thereof.

Abstract: Motor protector apparatus for independently sensing the respective positive, negative, and zero sequence currents flowing in the supply lines to a three phase motor for interrupting power to the motor whenever such positive, negative, or zero sequence components reach levels indicative of abnormal operating conditions. The protector network includes bridge means for segregating the negative and positive sequence components, indicators for visually displaying the source of the abnormality, and means for restoring power to the motor after a defined time period.

Abstract: An electrical protection unit having a plurality of main leads for respectively interconnecting a plurality of lines of an electrical power source to at least one electrically operated unit. At least one main lead has a device therein for opening the respective lead when the device is activated. The one main lead has one side of an electrical circuit interconnected thereto with the other side of the circuit being adapted to be interconnected to ground, the circuit having means for activating the device when the circuit is operatively interconnected to ground. Control means are provided for operatively interconnecting the circuit to ground.

Abstract: A mains safety isolating device is provided for an audio device e.g. guitar and microphone for preventing fatal electrical shock upon grounding breakdown and in which a transformer has a primary winding grounded at a point and connected to an electro-acoustic transducer to receive electrical signals therefrom, a secondary winding of said transformer is connected to a primary winding of a second transformer by signal conductors, a secondary winding of said second transformer being connected to the amplifier circuit of a mains powered amplifying and loudspeaker apparatus, said secondary winding being grounded at a second point separate and isolated from the first-mentioned point.

Abstract: A current sensor provides a positive voltage when a non-desired condition is present, such as rotation of machinery above a predetermined speed, and a gating circuit causes contacts of a relay to close whenever the rotational speed drops below such predetermined speed, that is when the desired condition is achieved. The gating circuit also closes these relay contacts in response to failure of the electrical power to such gating circuit. The circuit includes a P-N-P transistor in series with the relay coil, which transistor is switched on or off by a NAND gate. A low level signal to the base of the P-N-P transistor is provided through the NAND gate when the inputs to the gate are high, thereby providing a fail-safe feature for the relay because one of the NAND gate inputs is provided from the sensor's reference voltage through a Schmitt-trigger circuit.

Abstract: A solid state switching circuit for applying rectified alternating current to one or the other of two solenoid valve actuators and modulating that current from a pull-in value to a lower holding value has a separate power circuit for each solenoid and a common timing and trigger circuit. Each power circuit contains a pair of diodes and a pair of silicon controlled rectifiers connected in a bridge circuit to supply its solenoid. The common timing and triggering circuit is connected to be energized whenever either power circuit is energized and contains a first DIAC control circuit for supplying triggering pulses early in each AC cycle and a second DIAC circuit for supplying pulses late in each AC cycle. The DIACs feed a coupling transformer which is coupled to the silicon controlled rectifiers of both power circuits. A time delay circuit biases a transistor to the on state after a predetermined time interval to disable the first DIAC control circuit.

Abstract: Method and apparatus for enhancing charge retention of a photosensitive layer wherein an ion wind is created and applied to the photosensitive material prior to its reuse. The apparatus preferably comprises a corona charging unit having an opening and directing means adjacent the opening for directing the flow of ions created during corona charging into an uncharged portion of the photosensitive layer.

Abstract: The invention is directed to an arrangement which serves to detect deficient operational capability of vacuum switching vessels and which causes a signal to be given if a fault affecting the operability occurs. Instead of the signal, a protective device alone or together with the signal can also be caused to respond. According to the arrangement of the invention, the electromagnetic radiation emanating from the vacuum switching vessel is gathered by means of a detector and evaluated for providing the signal or initiating the action of the protective device. The range of the electromagnetic radiation in the region of thermal radiation is especially suitable for use. The invention is suited particularly for application in switchgear equipped with vacuum switching vessels.

Abstract: Electrical equipment, such as telephone station apparatus, exposed to occasional, destructively high, voltage surges (e.g., lightning strikes) is protected by a device, placed in parallel with the equipment, including two electrodes defining a fixed narrow spark gap. Such a device is designed to spark over with each surge and to recover afterward, restoring the line to its original condition. The predominant failure mode of such devices is shorting across the narrow gap, due to electrode damage produced during the protective arcing mode. In the disclosed devices, the electrodes define a narrow region, determining the protective breakdown voltage, and a wider region, sustaining the major part of the electrode damage. Shortly after the initiation of the protective discharge in the narrow gap region, the discharge is forced into the wider gap region by the provision, in at least one of the electrodes, of a high resistance path at the narrow gap region.

Abstract: This disclosure relates to a protective relaying system for a polyphase power transmission line in which at least two separate line operating conditions at a remote end of a protected line section are transmitted to a local end of the line section over a single communication channel. In the preferred illustrated embodiment, the operating conditions of three-line conductors are sequentially transmitted whenever a fault condition is sensed on any one or more of the three-line conductors. During the normal, non-faulted operation, a coded signal is continually transmitted to maintain the time derived signals at the receiver in substantial synchronism with the time derived signals of the transmitter. The coded signal also establishes a trip inhibiting or guard signal at the receiver.

Abstract: An electric furnace supply transformer is inside of a room or vault where roof beams extend in cantilever fashion over a wall of the vault. Secondary buses from the transformer extend through clearance holes in the wall and engage with vertical posts that are supported on and electrically isolated from the cantilever beams. The posts have terminal members for connecting with the buses and with cables leading to the electric furnace electrodes.

Abstract: The disclosure relates to a time-overcurrent relay utilizing successive linear time-current segments which approximate a non-linear, inverse time-current curve the linear segments are determined by subtracting a series of ramp like voltages of increasing magnitudes from a series of bias voltages, each of which is of substantially constant magnitude and which bias voltage magnitudes decrease in sequence by the peak magnitude of the preceding ramp voltage.

Abstract: An improved overvoltage protection circuit for cascaded radio frequency signal distributing amplifiers interrupts a power transmission path in an open circuit mode responsive to an overrange input power potential, and is automatically reset to its quiescent operative condition when the overvoltage condition abates. AC energy is coupled by the instant arrangement at a reduced level while the fault condition persists, such that the driven load is continuously energized.In accordance with one aspect of the present invention, selective relatively essential ones of the distribution amplifiers, e.g. trunk amplifiers, can be maintained operative by a DC standby power supply during an AC line power hiatus. Correspondingly, other, less important amplifiers are automatically rendered inoperative during power faults to prevent excessive drain in the DC standby source.

Abstract: A structure affording ease of manufacture and assembly for a static eliminator of the type including an insulated conductor adapted for attachment to a source of high alternating voltage and a plurality of conductive members disposed along the cable insulation and including outwardly projecting needles capacitively coupled to the conductor to afford neutralization of static electrical charges in an area adjacent the needles. The conductive members are formed from a single thin piece of sheet metal and each comprises a channel generally U-shaped in cross section and having an inner surface adapted to engage the periphery of the insulation, with the needle being a U-shaped portion of the sheet metal bent to project away from the channel .

Abstract: An elongated base carries two uninsulated electric wires connected to a power source for providing a voltage difference between the wires. The base is placed in any area from which pests, such as rodents or birds, are to be removed. The base may be an electric cable which is to be protected from rodents. Where birds are involved, the base is an elongated perch of insulative material carrying two wires spaced apart by a distance small enough such that the foot of a bird alighting on the perch will touch both wires and be shocked. The perch may be a flexible cord strung between upstanding posts, or it may be a flat strip with both wires on one face of the strip. The perch may be arranged above a receptacle for catching a bird falling from the perch. A mirror may be arranged near the base, and means for reproducing or recording and reproducing bird sounds may be located near the base, for attracting a bird to the base. Electric power may be applied to the wires intermittently and at an adjustable voltage level.

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.

Abstract: A two path overvoltage arrester comprising two frustum-shaped main electrodes which have facing portions forming planar electrode surfaces facing toward each other and which are mounted into opposite ends of a tubular insulator member which also has a ring electrode mounted at its center and wherein both sides of the ring electrode as well as the planar electrode surfaces of the main electrodes are provided with relatively thin ring shaped attachments so as to provide hollow electrodes into which can be inserted an activation material.