Abstract: An active clamp circuit for controlling over-voltage, surge conditions in electrical circuits. The active clamp includes a varistor which is switched into a circuit by a high power switch upon the detection of a surge condition. The use of a MOS Controlled Thyristor ("MCT") as a means for the switching the varistor permits the circuit to withstand a high di/dt and surge current while maintaining both on and off gated control of the switch.

Abstract: A package for semiconductor devices with plural subelements and method of packaging. Semiconductor power devices may include plural subelements to increase device manufacturing yield. Each subelement is separately contacted through the lid of the package by attaching a foil to a subelement contact and depending a tab from the foil that extends through the lid. Tabs for operative subelements can be connected external to the package, and tabs for inoperative subelements may be left unconnected or covered so that electrical connections cannot be made therewith.

Abstract: The sensitivity of breakdown voltage to temperature and dV/dT induced currents is reduced in semiconductor power devices having a wide base transistor. The sensitivity is reduced by diverting current from the emitter of the wide base transistor to the base of the wide base transistor (an emitter short that does not reduce breakdown voltage) or by injecting a current into the base of the wide base transistor to its collector (an injected current that may lower the breakdown voltage, but no more than that related to temperature and capacitive current). The invention finds application in both epitaxial grown and substrate based devices.

Abstract: A hermetic semiconductor package having a ceramic lid with the device leads extending vertically through the lid is disclosed. The leads are mechanically retained within the apertures in the lid and direct bonded to the lid to provide a hermetic seal and a substantial lead density.

Abstract: A hermetic semiconductor package includes a ceramic lid with the device leads extending vertically through the lid. The leads are mechanically retained within the apertures in the lid and direct bonded to the lid to provide a hermetic seal and a substantial lead density.

Abstract: A hermetically sealed package for a semiconductor device includes a lid through which the leads of the device extend vertically away from the chip through an aperture in the lid which is hermetically sealed by the external terminal or electrode. The package is compact, lightweight and free of magnetic materials.

Abstract: A hermetic, high current package for a semiconductor device includes wide flat leads which are bonded to the contact pads of the device and formed to extend through apertures in an insulating lid. The lid is sealed to a base and the apertures around the leads are sealed with solder to provide the hermetic package. This package limits lateral current flow in the contact pads of the semiconductor device to relatively low levels which ensure the integrity of the contact pads.

Abstract: A hermetically sealed package for a semiconductor device includes a lid through which the leads of the device extend vertically away from the chip through an aperture in the lid which is hermetically sealed by the external terminal or electrode. The package is compact, lightweight and free of magnetic materials.

Abstract: A hermetic, high current package for a semiconductor device includes wide flat leads which are bonded to the contact pads of the device and formed to extend through apertures in an insulating lid. The lid is sealed to a base and the apertures around the leads are sealed with solder to provide the hermetic package. This package limits lateral current flow in the contact pads of the semiconductor device to relatively low levels which ensure the integrity of the contact pads.

Abstract: The invention comprises an improved cross-connect switch constructed from a plurality of switch modules for connecting input lines to output lines. The improved switch includes a switch module replacement system that allows a craftsperson to replace a switch module without interrupting connections between cross-connect switch input and output lines that utilize switch points in the switch module in question.

Abstract: A method and apparatus for detecting and locating defective crosspoint switches in a path consisting of a plurality of conducting segments connected by switch points is disclosed. The method and apparatus utilize the change in capacitance of the path which occurs when the switches are operated in a predetermined order.

Abstract: A temperature-responsive circuit, for operation with a load-control apparatus having a control input for adjusting the magnitude of power applied to a load from a source, uses: a sensor responsive to the temperature in the vicinity of the load-control apparatus; a subcircuit for converting the temperature sensed by the sensor to the magnitude of an electrical parameter; a subcircuit for providing a reference electrical parameter having a magnitude predeterminately selected to equal the magnitude of the electrical parameter at a maximum desired temperature T.sub.

Abstract: A voltage regulator circuit provides multiple control functions in respect to an automotive alternator including limiting of the field current to within a predetermined level. The regulator circuit includes a current control device for controlling the alternator field current, and a plurality of comparator networks to one of which is applied a field current reference signal and a sensing signal and to others of which are applied various alternator voltage reference signals and voltage sensing signals. The outputs of said comparator networks are employed in an OR fashion to control the field current control device.

Abstract: A battery monitor circuit for rechargeable multicell batteries that provides a reliable indication of battery failure independent of temperature, load and age, by continuously comparing the impedance of the cells of the battery against each other. Comparison means are provided responsive to a first voltage at a tapped terminal of the battery that divides the battery cells into two groups, and to a second voltage that represents a fraction of the battery voltage corresponding to the ratio of the number of cells in each group, said comparison means generating an error signal when said first and second voltages change so as to experience a reversal in relative magnitude, which is indicative of cell deterioration.

Abstract: An interface circuit for standard voltage regulator circuits that may be employed as an add-on component in an automotive electrical system for providing voltage regulation of the vehicle alternator in accordance with a given reference voltage that is in addition to the normal battery voltage regulation. The interface circuit includes a current control switching device coupled in the current path of the alternator field winding, and a control network responsive to the alternator output and the given reference voltage for operating said switching device in a duty cycle fashion so as to superimpose the additional regulation of the alternator voltage upon its normal battery regulation.

Abstract: A control circuit employed within an automotive electrical system for controlling the voltage transition rate between battery float and discharge levels in the presence of a switchable coupling between the battery and standard alternator. The control circuit includes means for regulating the alternator output voltage to said battery float level when the battery is coupled to receive charge current from said alternator, and for transforming said alternator output voltage to said discharge level at a predetermined rate prior to the battery coupling being switched to supply current to the load circuit, and further means for transforming said alternator output voltage to said float level at said predetermined rate after said battery coupling being switched to again receive charge current, whereby said predetermined rate provides a gradual change in the energization of said load circuit in the presence of the recited switchable coupling.

Abstract: A cooking cycle timer includes two timing circuits, each incorporating an oscillator and a counter. The first timing circuit times the first portion of a cooking cycle, and the second timing circuit times a predetermined second portion. At the end of the first portion, a visible indicator is turned on to indicate that the predetermined second portion of time remains in the cooking cycle. At the end of the second portion, and thereby the end of the cooking cycle, the visible indicator and an audible indicator are operated in pulsed fashion through the operation of a third oscillator. Visible indication is also provided during the first portion of the cooking cycle to show that the timing circuit is active.

Abstract: A cooking appliance, such as a deep fat fryer, includes programmable control system which monitors the operation of the cooking appliance and enables appropriate actions at proper times. The system includes a microcomputer which implements various timing and control functions. Control switches select operational states of the appliance. A diode matrix allows selection of input data. A multiplex circuit interconnects input signals to the microcomputer, a monitor circuit turns off the appliance if multiplexing stops. A temperature control circuit generates a signal responsive to the cooking fluid temperature and compares it with various reference signals under control of the microcomputer. A cooking control circuit generates a voltage proportional to the cooking fluid temperature, modifies it according to the desired doneness of the food being cooked, and converts it to a current which charges the capacitor in an oscillator.

Abstract: A method and apparatus for operating a smiconductor integrated circuit at minimum power from a voltage source, including deriving a semiconductor process parameter dependent reference voltage within the integrated circuit, comparing the magnitude of the reference voltage and the voltage source and maintaining the magnitude of the voltage source greater than the reference voltage.

Abstract: An emergency lighting system includes a high reactance transformer with a primary winding for connection to AC line voltage and a secondary winding. Circuit means are provided for monitoring the AC line voltage and includes means for coupling the transformer secondary winding to a non-linear load, a battery, during one AC half cycle and means for coupling the secondary winding to a linear load during an alternate AC half cycle to provide a DC voltage proportional to the AC line voltage.