Abstract: A battery monitoring circuit in a programmable controller generates a logic signal when it senses a low output voltage from a memory back-up battery. A controller processor is programmed to set a fault status bit and store it in a memory with input/output status data. The fault status bit is output to an I/O interface rack together with input/output status data during an I/O scan routine. The fault status bit generates a logic signal to a fault indicating device on the I/O interface rack to signal an under-energized memory battery in the controller processor.

Abstract: A disconnect switch includes a crossbar assembly having an arm at each of its ends which rotatably fastens the assembly to a frame for swinging motion around a pivot axis. Three movable contact assemblies are carried by the crossbar between a closed position in which their line side ends engage stationary contacts and an opened position in which their line side ends are disengaged. Stationary connectors aligned along the pivot axis engage the load side ends of the movable contact assemblies at all positions of the crossbar.

Abstract: A programmable controller with a processor module, one or more I/O modules and a rack in which the modules are supported, is expanded by replacing the processor module in a lead slot with a rack adapter module that connectes to a separate processor unit. The rack unit is converted from a controller rack to one of several I/O interface racks that can be connected to the separate processor unit. The removable processor module integrates the processing functions of the separate processor unit and the parity checking, decoding and buffering functions of the rack adapter module. The rack enclosure provides a universal connecter between the I/O modules and the module selected for insertion into the lead slot.

Abstract: A mechanical latch attachment (20) for a control relay (21) includes a mechanical latch movement (77), a solenoid (49), and a pair of contact cartridges (33) that are disposed in a housing (25). The wear-resistant latch movement (77) has a latch (95) with teeth (103) on one end that are engaged by a pair of pivotable, hooked pawls (105). The latch (95) is coupled to an operating plunger (79) through a contact actuator (82). The operating plunger (79) can be coupled to a conventional control relay (21), which moves the plunger (79) upon the closing of its relay armature (30) to actuate the contacts (35, 36) in both the relay (21) and the attachment (20) and to move the latch (95) to a position where it is restricted by the pawls (105). The restriction of the latch (95) holds the relay armature (30) closed and the contacts (35, 36) actuated even though the relay (21) is deenergized.

Abstract: A packaged electronic component includes an insulating body completely enclosing the electronic component except for runner-like blade leads which extend outwardly from the insulating body. The runner-like blade leads are more durable than conventional shaped leads and facilitate the making and breaking of sliding electrical contact with stationary contacts. A method of preparing the novel, packaged electronic component is also disclosed.

Abstract: A numerical control system includes a main processor which performs such functions as interpolation and outputting of motion command signals to the servomechanisms on a machine tool. A separate programmable interface processor connects to the main processor bus structure and it operates as a programmable controller to control the discrete digital I/O devices associated with the machine tool. A third processor couples through a serial data link with the main processor and it operates to service peripheral I/O devices associated with the front control panel on the numerical control system.

Abstract: A vernier control (10) with independent coarse and fine adjustments includes a track pattern (17) that is formed along three concentric rings on a single base (11). A horseshoe-shaped, low-resistance track (17a) extends around a segment of the inner ring and has a pair of termination tracks (17d, 17e) connected to its opposite ends and extending in reverse directions in opposite half-sections of the intermediate ring. A pair of high-resistance tracks (17b, 17c) are formed in opposite half-sections of the outer ring, each extending alongside a respective termination track (17d, 17e). A fine adjustment rotor (16) is journaled in the base (11) in the center of the track pattern (17), and carries a fine adjustment contact (15) that engages both a collector terminal (19) on the base (11) and the low-resistance track (17a). An annular contact carrier (12) is mounted for rotation around the rotor (16) and carries a pair of coarse adjustment contacts (13 ).

Abstract: An electrical resistor element and method of manufacturing the same. The element may comprise a fixed resistor or may be the resistive and collector component of a variable resistor. In either case, the element comprises, at least as a portion thereof, a substrate comprising an insulating substrate injection molded from ceramic-glass frit material and organic binder and lubricating material. A layer of resistive material and a layer of conducting termination material are each deposited on the unfired substrate. The organic materials in the substrate and its termination and resistive layers are substantially "burned out" prior to simultaneously co-firing the substrate and the deposited resistive and termination layers.In the case of fixed resistors, the element may be molded as a half-shell arranged to receive leads extending from opposite ends of the half-shell molding and attached by soldering or other means to the termination areas.

Abstract: A method of monitoring open phase, phase reversal and voltage unbalance conditions in a polyphase source includes shifting the phase of signals which are proportional to the line voltages in a three-phase A.C. power source by 180.degree., +60.degree., and -60.degree., respectively, and summing the phase-shifted signals to generate a signal which is proportional to the negative-sequence component of the three-phase line voltage. This signal is rectified and compared with a reference signal. If a net negative-sequence signal is generated over a sufficient time period a positive output signal decreases until it crosses a switching threshold to disconnect a load from the source. The output signal will not rise again to the switching threshold, thereby allowing reconnection of the load, until the negative-sequence signal subsides and is less than the reference signal. A circuit is disclosed with three operational amplifiers and two passive filters to carry out the invented method.

Abstract: A rheostat (10) has a disk-shaped base (11) that is slidably mounted between a pair of spaced terminal pins (12, 13). A resistance track (14) is disposed on top of the base (11) and is connected to a collector track (15) that is disposed around the circumference of the base (11). A collector terminal pin (12) has contacts (12d) in sliding engagement with the collector track (15), and a wiper terminal pin (13) has an oblique contact surface formed by projections (13g) that slidably engage the resistance track (14). The terminal pins (12, 13) can be mounted on a supporting surface, so that as the base (11) is rotated, the resistance between the terminal pins (12, 13) is varied. The oblique contact surface on the wiper terminal pin (13) aids in maintaining a balanced current distribution in the resistance track (14).

Abstract: A microprocessor based program loader is connected to the memory data bus and memory address bus of a programmable controller. The program loader is responsive to commands entered through a keyboard to load and edit the programmable controller control program. A mode switch associated with the programmable controller provides a number of selectable positions which determine the mode of operation of the programmable controller and the functions that can be performed by the program loader. One of the positions on this mode switch enables the program loader through a control line to assume control of the mode selection. The operator can thus control the mode of operation through the program loader keyboard which may be located remotely from the programmable controller.

Abstract: An SCR is connected across one of three line contacts which couple the power lines to the windings of an a.c. motor. When the line contacts are opened to shut down the motor, heating current is applied to one of the motor windings through the SCR to raise its temperature above the ambient dew point. The SCR is fired every cycle of the line current and the firing angle is controlled in response to a command signal to provide the proper amount of heating current in the motor winding. The command signal is generated by summing a preselected reference signal with a negative feedback signal which is indicative of the amount of motor heating.

Abstract: A method of assembling a packaged microcircuit with face-mounted leads includes forming a lead frame into a holder with opposed sets of leads turned upward and angular to spaced apart carrier strips, and securing a substrate having a microcircuit thereon within the holder with one set of leads securely held in contact with terminals on a face of the substrate, so that bonded electrical connections between the leads and the terminals can be readily made with conventional soldering techniques.

Abstract: An electrical circuit device having a substrate including circuit components on at least one side thereof and a plurality of through openings in the substrate. Terminal leads are positioned in the openings each with a deformation intermediate the ends of the leads and spaced internally of the opening from a soldered area at the juncture of the exposed portion of the leads and the termination edge of the substrate. Two methods of assembly of leads to the substrate are also disclosed.

Abstract: A trimming potentiometer (10) has a circuit track pattern (12) disposed on a base (11) having three integrally formed legs (11d). The track pattern (12) includes a collector track (12a), a resistance track (12b) and a pair of termination tracks (12c) connected to opposite ends of the resistance track (12b). Terminals for the device are formed by extending the collector track (12a)and the pair of termination tracks (12c) down the middle leg (11d) and the opposite outside legs (11d), respectively. A multi-functional contact (13) is rotatably mounted on the base (11) and includes multiple fingers (13g) that contact the resistance tracks (12b), dimpled areas (13j, 13k) which form projecting surfaces that contact the collector track (12a), a stop tab (13l) at its upper extremity that limits rotation, and outwardly extending notched tabs (13m) for receiving a suitable drive member to adjust the setting of the potentiometer (10).

Abstract: A time delay type of switch actuating mechanism is shown that can be assembled for either an "on delay" or "off delay" operation. A pair of contact carriers are mounted for linear motion, and a pivoted rocker member is joined between them for coordinating their movements. The rocker member has a lost motion connection with each contact carrier, and a catch is provided to restrain movement of the rocker and contact carriers until a timer performs a timing function. At the end of the timing interval the catch is released to permit a loaded spring to move the contact carriers and rocker to complete a switching function that is time delayed.

Abstract: An improved movement for a time delay relay cooperates with an electromagnet and a timer to provide either "On Delay" or "Off Delay" operation of the relay contacts. The movement has an elongated operating plunger that is movable in forward and backward strokes, a latch, and a contact actuator coupling the latch to the relay contacts. A pair of springs are disposed in a spring cage formed in the actuator and at least one spring-compressing flange is carried by the plunger and disposed between the springs. In the on delay mode of operation, one spring is loaded against the actuator upon a forward stroke of the plunger. In the off delay mode of operation, the other spring is loaded against the actuator upon a backward stroke of the plunger. The latch is restrained upon the movement of the plunger to load one of the springs, and is subsequently released from its restraint after a time delay to operate the relay contacts with spring action.

Abstract: A programmable controller sequentially executes a control program at a basic "scan rate" determined by the length of the program and the speed at which the controller processor executes the instructions therein. At the completion of each scan through the control program an I/O scan is performed which inputs the status of all sensing devices to the controller image table and outputs status data from the image table to operating devices. The present invention enables the status of selected sensing devices to be inputted and acted upon at any point during the scan through the control program and it enables the output of the processor logic unit to be coupled to a selected operating device at any point. The rate at which selected I/O devices can be scanned by the controller is thus programmable and may be much higher than the basic scan rate of the controller.

Abstract: A pressure control assembly having a snap-acting Belleville washer responsive to fluid pressure, and a switch actuating mechanism movable therewith, includes an adjusting mechanism for the snap-acting Belleville washer. The adjusting mechanism includes at least one pin which can be moved along the surface of the Belleville washer to change the Belleville washer's pivot point by increasing or decreasing its lever arm, thus varying its snap pressure. In the preferred embodiment, there are three pins which extend through aligned slots in an upper and lower plate and the pins can be moved radially inwardly and outwardly by rotating the lower plate relative to the upper plate.

Abstract: An eight-bit microprocessor sequentially reads controller type instructions from a memory and applies the operation codes of selected ones of the instructions to a hardwired Boolean processor. The microprocessor also couples status words between an I/O image table stored in the memory and the I/O interface racks which connect the programmable controller to the machine being controlled. In general, those controller type instructions which are word oriented are executed by the microprocessor and those which are single-bit oriented are executed by the Boolean processor. The Boolean processor is operable in combination with the microprocessor to examine selected status bits in the I/O image table and to set selected status bits therein to a logic state which is determined in part by the state of the examined status bits.