Abstract: In an electromechanical relay the core of the relay coil and a corresponding zone of the armature are each provided with a pole face of zig-zag or stair-step configuration. A succession of corresponding edges of the core and armature pole faces concentrate the magnetic flux to increase the initial force on the armature and to limit the closing force as the armature reaches the closed position. The armature bearing is shaped to create a longitudinal wipe motion. The relay exhibits faster and quieter action with less bounce and reduced contact chatter.

Abstract: A baseboard radiator element is formed of an aluminum tube and fins or vanes of aluminum sheet. An elongated strip of sheet aluminum is bent into a fin assembly of generally rectangular fins alternating with spacer members, with the fins having central apertures. The fin assembly is placed into a fixture and the tube is forced through the aligned apertures to create strong mechanical and thermal contact between tube and fins. The fin structure can be used with center tubes of other materials. A brass or steel connector insert is fitted into the end of the aluminum tube, and the end of the tube is deformed inward using a collet or jaw device to create a hermetic seal with the tube. The process can also be used for joining aluminum tubing to tubing of aluminum or other materials.

Abstract: A voltage or power conditioning and control device may be used in line with a source of AC line power and a reactive load such as a single-phase induction motor. The device operates to absorb some of the power reflected by the AC load and generate a synthetic power wave to supplement and correct the applied power in level and phase. The device employs a pair of power capacitors, and a pair of electronic switch devices each with a diode in parallel. Gating or command signals are generated based on the line voltage and timing, e.g., zero crossings. The phase or timing of the command signals is selected for a normal or no-boost mode, a voltage boost mode, or a voltage reduction mode. The capacitors are considered in series with the load, and improve the power factor to the load. A variation of this device may be used in conjunction with a solar array or other local power source.

Abstract: A baseboard radiator element is formed of an aluminum tube and fins or vanes of aluminum sheet. An elongated strip of sheet aluminum is bent into a fin assembly of generally rectangular fins alternating with spacer members, with the fins having central apertures. The fin assembly is placed into a fixture and the tube is forced through the aligned apertures to create strong mechanical and thermal contact between tube and fins. The fin structure can be used with center tubes of other materials. A brass or steel connector insert is fitted into the end of the aluminum tube, and the end of the tube is deformed inward using a collet or jaw device to create a hermetic seal with the tube. The process can also be used for joining aluminum tubing to tubing of aluminum or other materials.

Abstract: A relay situated in series between an AC line source and an AC load has a core conductor connected with the fixed N.O. contact, so that load current flows axially through the core of the actuator coil. Alternatively, the fixed N.C. contact may be connected with the core conductor. A plate armature with leaf springs can achieve linear axial action. A sensor connected to leads of a winding of the actuator coil picks up a an induced voltage that is representative of the current supplied to the load. This provides a simple arrangement for monitoring for current level and can be used for measuring power factor or ?? at the load device. In a three phase embodiment, phase imbalance can be detected.

Abstract: An actuation circuit for an electromechanical relay employs a microprocessor and a switching transistor to actuate a relay over a wide range of applied voltages. The switching transistor is connected in series with the actuator coil. A voltage sensing circuit is connected to one input of the microprocessor, which produces a pulse-width modulated actuator output to gate the switching transistor. The microprocessor is suitably programmed so as to produce a pulse width modulated signal actuator signal whose duty cycle is a function of applied voltage. The RMS current through the relay coil is sufficient to ensure good actuation, but does not overstress the coil. The relay is selected to have its rated actuation voltage at or below a lower end of the expected range of applied voltages. A relay actuation boost arrangement can include a transistor or an SUS (silicon unidirectional switch) or similar negative resistance device.

Abstract: Arrangement for interrogating multiple switch conditions employs a single input microprocessor for a plurality of switch elements that are coupled in series with an operating element and a power source. A variable oscillator has a control input and an output coupled to the microprocessor input, providing a periodic signal to the same. A plurality of impedance elements, e.g., resistors, each with a respective value, are coupled between a respective junction between two successive switch elements and the control input of said variable oscillator, such that the rate of said periodic signal varies as a function of the open or closed condition of the respective switch elements. For each switch being tested, the microprocessor looks for one predetermined frequency or pulse rate corresponding to an open condition and another corresponding to a closed condition.