Abstract: ECL bus driver circuits for multi-driver net use are provided with a disable transistor that has its emitter coupled to the emitter of the pull-down transistor of the driver so that when the disable circuit of a driver is activated, the coupled pull-down transistor is not able to sustain current flow through its collector-emitter path, and when the disable transistor is turned off, the pull-down transistor enables the drive circuit to function in its normal manner.

Abstract: A system for and a method of generating a four phase clock signal is disclosed. The system includes an oscillator circuit that generates a clocking signal of frequency F. A flip-flop, under control of a Master Clear signal, establishes the first stage of a shift register in an active state while the clocking signal drives the shaft register to serial, end-around, shift the active state through the shift register. The parallel outputs of the shift register are coupled to respectively associated pulse generators which are also triggered by the clock signal to emit the four phase clock signal therefrom. The method ensures that the first phase signal is always the first signal to be emitted from the system while compatible semiconductor circuitry is used throughout and is operated at or near the frequency limit of the semiconductor circuitry used.

Abstract: A first sensor for the detection of dielectric failure (by burning) within a multilayer printed circuit assembly comprises an isolated conductive layer. This first sensor is connected by a first diode to a single wire which also connects a second, temperature, sensor via a second diode (system ground is a return). A number, nominally 16, of such single wire connected sensor pairs are selectable in accordance with an externally (microprocessor) furnished address. During a first time period, an externally (microprocessor) selected interrogation of temperature causes a first, positive, voltage bias to be applied to the selected sensor pair resulting in a current linear with temperature (over the range of 0.degree. C. to 100.degree. C.) in the second sensor. This current is transformed to voltage, offset by 273.degree. Kelvin, amplified, and converted to a digital value for issuance to an external (microprocessor) requestor.

Abstract: A first sensor for the detection of dielectric failure (by burning) within a multilayer printed circuit assembly comprises an isolated conductive layer. This first sensor is connected by a first diode to a single wire which also connects a second, temperature, sensor via a second diode (system ground is a return). A multiplicity, nominally 16, of such single wire connected sensor pairs are selectable in accordance with an externally (microprocessor) furnished address. During a first time period, an externally (microprocessor) selected interrogation of temperature causes a first, positive, voltage bias to be applied to the selected sensor pair resulting in a current linear with temperature (over the range of 0.degree. C. to 100.degree. C.) in the second sensor. This current is transformed to voltage, offset by 273.degree. Kelvin, amplified, and converted to a digital value for issuance to an external (microprocessor) requestor.

Abstract: A clock source for timing and synchronizing the operation of digital data processing equipment and having automatic duty cycle correction is described. A source of signals provides clock signals at a predetermined frequency. A buffer circuit provides the true and complement clock signals to low pass filters that function to filter the true and complement clock signals to DC levels proportional to the duty cycle of the source signals. The DC voltages represent instantaneous deviation voltages from a known reference and are applied to a differential amplifier circuit for providing a feedback signal for adjusting the duty cycle of the clock output pulses that are available. One embodiment has the source of signals directly coupled to the buffer circuitry and utilizes the feedback signal to adjust the duty cycle of the signal source circuitry. A second embodiment has the source signals capacitively coupled to the self-correcting circuitry and the feedback signals adjust the duty cycle of the clock output signal.

Abstract: A first sensor for the detection of dielectric failure (by burning) within a multilayer printed circuit assembly comprises an isolated conductive layer. This first sensor is connected by a first diode to a single wire which also connects a second, temperature, sensor via a second diode (system ground is a return). A multiplicity, nominally 16, of such single wire connected sensor pairs are selectable in accordance with an externally (microprocessor) furnished address. During a first time period, an externally (microprocessor) selected interrogation of temperature causes a first, positive, voltage bias to be applied to the selected sensor pair resulting in a current linear with temperature (over the range of 0.degree. C. to 100.degree. C.) in the second sensor. This current is transformed to voltage, offset by 273.degree. Kelvin, amplified, and converted to a digital value for issuance to an external (microprocessor) requestor.

Abstract: A cooling system monitoring assembly incorporating a heat generating element for simulating heat generation of components in the system, together with heat sensing element responsive to the heat generating element for providing temperature signals when the temperature of the heat generating element is sensed to have exceeded a predetermined threshold is described, thereby indicating the level of temperature fault. A support assembly is described for supporting the heat generating element in the heat transfer relationship to the monitored cooling system, while supporting the heat sensing element. A system for monitoring a plurality of subassemblies associated with the monitored cooling system and identifying the location of detected temperature fault condition is also described.

Abstract: An electronic circuit controls a non-linear electromechanical valve in order that the temperature of approximately 25 gallons of coolant water within a reservoir may be maintained within +2.8.degree. C. to -0.0.degree. C. of a set point temperature from 35.degree. F. to 100.degree. F. The valve regulates circulation of such coolant within a secondary cooling loop incorporating a non-linear heat exchanger for thermal exchange with building water flowing from 20 to 30 gallons per minute. The reservoir coolant water is subject to an essentially instantaneously variable thermal load of 0 to 20 kilowatts due to circulation through logic modules in a primary coolant loop. The electromechanical valve control circuit receives an external set point temperature signal, and a reservoir coolant temperature signal which is offset in conversion from degrees Kelvin to degrees Centigrade.

Abstract: Apparatus for distributing evenly delayed digital signals to a plurality of separate physical locations in which each location utilizes one particular digital signal. At each physical location an apparatus for adjusting the timing delay of the digital signal is provided so that all physical locations may utilize the digital signals, as for example, a pulse from a timing chain, at the same instant of time with respect to each other. The apparatus for adjusting the timing delay at each location includes a receiver for accepting the digital signal. After the receiver, the digital signal is routed to both a delay line capable of providing a plurality of time delays and to a selector having an input for the received digital signal and for each one of the time delays provided by the delay line. Finally, each selector provides a means of selecting just one of the signals to be utilized at that physical location.