Abstract: A panel locating method engages holes in a panel which are located in the panel symmetrically about a fixed point and axis and applies synchronized opposing displacements of engaging elements to locate and secure the panel on a work surface.

Abstract: A technique for assembling a transformer core from two separate core components uses a thermo shrinkable elastomer band or tubing in place of the more conventional glues and metallic clips to secure the component into a unitary structure. A thermo shrinkable mylar plastic tubing is placed around a periphery of a core formed by abutting two separate core components together so as to form a closed magnetic path. Application of heat shrinks the tubing and secures the two separate core components into one unitary core structure.

Abstract: In a local data distribution network configuration a plurality of bidirectional data distribution busses are each connected to a bus master control circuit at a terminal end of the bus. Connected to each of the data distribution busses are a plurality of passive outlets to which intelligent connectors or stations may be connected. Each station has a unique address and is utilized for individually coupling data processing devices to the bus. Grouped pluralities of the bus master control circuits are included within a bus termination hub facility. Data from any of the bus master control circuits may be transferred by the bus termination hub via a data trunk as part of a star type configuration, to a central switching circuit such as a virtual circuit switch. Direction of data flow on each of the bidirectional busses and periodic temporary synchronization of the stations is controlled in response to signals transmitted to the bus by the bus master control circuitry associated with that bus.

Abstract: A UPS system includes a backup input line isolation switch and control circuit for energy flow in the UPS is operative, during operation of the reserve energy source portion of the power supply in supplying power to the output, to provide mechanical isolation between the primary energy source connected to the input line and the secondary energy source upon detection of a failure of an electronic isolation switch normally providing isolation between te input line and the secondary energy source or an output of the UPS.

Abstract: A UPS system includes a mechanical backup input line isolation switch to provide mechanical isolation between the primary energy source connected to the input line and the secondary energy source upon detection of a failure of an electronic isolation switch normally providing isolation between the input line and the secondary energy source. Detection of such a failure is accomplished by means of a dummy load which is connected in across the input line. Its impedance is sized to permit a small low level of current flow, above normal leakage current levels permitted by a functioning semiconductor electronic line switch, if energy is reverse coupled from the reserve energy source via a failed electronic line switch without draining significant power from the primary energy source when the UPS is normally operative and deriving power from the primary energy source.

Abstract: A four surface point type drill has its primary clearance faces configured so that their circumferential width decreases as the longitudinal axis of the drill is approached. The trailing edge and cutting edge of the primary clearance face surfaces substantially intersect each other at a point where they both intersect the opposite ends of the chisel edge of the drill point. The chisel edge itself is totally defined by a line formed by the intersection of the two secondary clearance face surfaces of the drill point. This new improved drill point geometry permits the use of reduced primary and secondary clearance face relief angles at the drill point which improves the structural integrity of the cutting edge of the drill and hence reduces chipping at the cutting edge.

Abstract: A single ended forward converter includes a snubber/reset circuit that diverts current flow from the power switching transistor during the turn off transition to significantly reduce switching loss therein. This same circuit is further operative to resonate energy stored in the magnetizing inductance of the power transformer with a capacitor during a nonconducting period of the power switching transistor in order to reverse the polarity of current, in the magnetizing inductor and reset the core, and further obtain bipolar flux excursions in the transformer core during each cycle of operation.

Abstract: A memory accessing control for a microcomputer system is compatible with both static and dynamic type memories. A gating circuit is responsive to read/write and address latch enable control signals of a microprocessor, and provides an enable signal utilized to generate a chip enable signal compatible with the timing and control requirements of both dynamic and static memories.

Abstract: An electrical component for mounting on a circuit substrate densely populated with conducting paths, includes interconnecting conductor paths included within the electrical component and unrelated to the electrical device supported by the component support structure in order to provide an interconnection between two conducting paths of the circuit substrate.

Abstract: A MOSFET gate driver circuit reduces the noise susceptibility of a MOSFET switch by utilizing dual drive paths to apply turn-on and turn-off bias signals to the gate of the MOSFET. Drive pulses are coupled to the MOSFET switch via a pulse transformer which has two serially connected secondary windings. Turn-on pulses are coupled by a diode from the first secondary to the MOSFET gate. Turn-off pulses are coupled via the second secondary to a control MOSFET which is turned on by a turn-off pulse and remains on in order to keep the gate of the MOSFET switch to a hold off voltage.

Abstract: An off-line switcher includes an auxiliary winding on the secondary side of the power transformer coupled by a power switch to a secondary voltage source in order to provide uninterruptible power to the output from either a primary AC or a secondary DC source. The power switches coupling both primary and secondary source voltages to the power transformers are driven at identical duty cycles by a common regulation control. Differing transformation ratios between primary and secondary sources of power define different operational ranges and determine flow of power based on the magnitude of the primary source of power.

Abstract: An off-line regulating power supply utilizes a regulating transistor which perates in a dissipative mode for only a portion of each half cycle of an input AC voltage in order to regulate an output voltage by truncating the input AC sinewave. This AC input signal is full wave rectified and coupled to a primary winding of a power transformer through the regulating transistor. One of a plurality of secondary windings is coupled to a voltage threshold detector which responds instantaneously to attainment of the threshold in each half cycle of operation to bias the regulating transistor from a saturated condition to an active dissipative impedance state which limits the output voltage to the threshold level. As the input AC sinewave peaks and declines in value, the regulating transistor is again biased into saturation when the voltage applied to the threshold detector drops below the threshold level.

Abstract: A voltage regulator circuit for a switching type converter operates by applying full power to the output if it falls below a reference value and zero power if the reference value is exceeded. The switching device of the voltage regulator is operated at a first high frequency and is periodically enabled to supply power to the output for discrete operative clock cycles at a second lower clock frequency in accord with the output signal level. An interval of off-time follows each operative cycle.In another embodiment operation of the switching devices is continuous, but power flow to the output is significantly reduced when the output voltage is overlimit.

Abstract: A microprocessor system is adapted to permit the accessing of peripheral devices that have slow data bus release times without acquisition conflicts by placing the microprocessor in the hold state after the data acquisition. Logic circuitry responsive to the hold state supplies control signals to the peripheral devices over the bus during the hold state. At the end of one hold state, normal operation is resumed.

Abstract: A single ended forward converter periodically resets the transformer core to prevent saturation and returns magnetizing energy to the energy source, requiring only the addition of one resonating capacitor to the converter circuit.The transformer is reset and the energy recovered into the input voltage source by resonant commutation of the magnetizing current between the magnetizing inductance and a resonating capacitor. A resonant current path is completed during a nonconducting interval of the power transistor switch through a resonating capacitor, shunting the output rectifying diode connected to the secondary winding, and the flyback diode of the output filter to permit transfer of the transformer's magnetizing energy to the input energy source. This magnetizing energy transfer from core to capacitor to input energy source has a resonant quasi-sine waveform and utilizes the resonant properties of the network to enable its flow back into the input voltage source.

Abstract: A self-oscillating power converter utilizes a MOSFET power transistor switch with its output electrode coupled to a tuned network that operatively limits the voltage waveform across the power switch to periodic unipolar pulses. The transistor switch may be operated at a high radio frequency so that its drain to gate interelectrode capacitance is sufficient to comprise the sole oscillatory sustaining feedback path of the converter. A reactive network which is inductive at the operating frequency couples the gate to source electrodes of the transistor switch and includes a variable capacitance as a means of adjusting the overall reactance, and hence the converter's switching frequency in order to provide voltage regulation. A resonant rectifier includes a tuned circuit to shape the voltage waveform across the rectifying diodes as a time inverse of the power switch waveform.

Abstract: A switching converter in which current mode voltage regulation is implemented includes circuitry to add ramp compensation to the sensed current signal at light load and reduce or disable this ramp signal compensation at heavy load. This load dependent ramp signal improves the stability of operation of the converter and maintains its inherent current limit performance over a wide range of loading. An alternative connection allows for disabling the current sense signal and hence, transforming the current mode to voltage mode control under light load.

Abstract: A rectifier plant control system includes a stored program of a master control to control operation and monitor rectifier plant conditions. The master control is designed to cooperate with optional control systems to accomplish new operations without requiring modifications to the stored program control of the master control. One such optional control system permits accessing the master control from a remote location.The optional control system includes an associated stored program which is utilized by the master control to accomplish the option. This associated stored program is in an address field of the stored program of the master control and is executed by the master control.

Abstract: An inductor structure is combined with a ferroresonant regulator as a filter inductor in one instance, and as a regulating inductor in another. In one example, a ferroresonant voltage regulator includes a pair of shunt filters at its output to reduce the low order odd harmonic content of the AC output. The filtering arrangement includes two LC shunt filters having their independent inductor windings wound on a single magnetic core unit. Auxiliary windings coupled to each of the inductor windings are placed in series with the output to buck any remaining harmonics.In a second instance, independent regulating inductors in a multiphase ferroresonant regulator are also realized on a single magnetic structure.

Abstract: A switching type power supply includes neutralizing circuitry to counteract current flow to equipment ground due to generated RF currents. This neutralizing circuitry includes an added transformer winding and a neutralizing capacitor to counteract and cancel specified leakage currents. This arrangement permits use of smaller filter capacitors and hence reduces the line frequency leakage current flow to equipment ground.