Abstract: A voltage margin circuit has an input that receives a control voltage for programming an output reference voltage. The control voltage is coupled through an input resistor to an operational amplifier, referenced to a voltage midway between the voltage range of the input voltage and having its output coupled to a pair of transistors, whose current flow paths are coupled to inputs of a first pair of current mirrors. Outputs of the first current mirrors pair are cross-coupled to inputs of a second current mirrors pair. Outputs of the second current mirror pair are coupled through an output resistor to a prescribed voltage. The output reference voltage is the sum of the prescribed voltage and an offset as the product of the output resistor and an output current supplied by one of the third and fourth current mirrors.

Abstract: A voltage margin setting interface circuit has a single input pin, and is configured to program the slew rate and polarity direction of variation of the operation of a digital-to-analog converter, such as may be used to set a reference voltage level, for application to an error amplifier of a voltage regulator circuit of the power supply of a personal computer. A DAC clocking control circuit is coupled to an output port, and to respective DAC increment and decrement ports, and is operative to control the magnitude of output current, and to assert an output signal at one of the increment and decrement ports, in accordance with a prescribed relationship between the voltage and upper and lower ranges of the input voltage relative to its middle value.

Abstract: A voltage margin circuit has an input that receives a control voltage for programming an output reference voltage. The control voltage is coupled through an input resistor to an operational amplifier, referenced to a voltage midway between the voltage range of the input voltage and having its output coupled to a pair of transistors, whose current flow paths are coupled to inputs of a first pair of current mirrors. Outputs of the first current mirrors pair are cross-coupled to inputs of a second current mirrors pair. Outputs of the second current mirror pair are coupled through an output resistor to a prescribed voltage. The output reference voltage is the sum of the prescribed voltage and an offset as the product of the output resistor and an output current supplied by one of the third and fourth current mirrors.

Abstract: A voltage margin setting interface circuit has a single input pin, and is configured to program the slew rate and polarity direction of variation of the operation of a digital-to-analog converter, such as may be used to set a reference voltage level, for application to an error amplifier of a voltage regulator circuit of the power supply of a personal computer. A DAC clocking control circuit is coupled to an output port, and to respective DAC increment and decrement ports, and is operative to control the magnitude of output current, and to assert an output signal at one of the increment and decrement ports, in accordance with a prescribed relationship between the voltage and upper and lower ranges of the input voltage relative to its middle value.

Abstract: An absolute value circuit includes an operational amplifier, the output of which is coupled to control inputs of complementary polarity transistors having current flow paths therethrough coupled in series with inputs of current mirror amplifier stages. A common node of the current flow paths through the transistors is coupled to an input of the operational amplifier to which a current waveform is applied. The current mirror amplifier stages are configured so as to provide like polarity output currents. The outputs of the current mirror amplifier stages are combined to produce an output current that corresponds to a full wave rectification or absolute value of an input current coupled to the operational amplifier.

Abstract: A hydraulic flow valve apparatus having a valve body providing a valve body cavity with an eccentric sidewall. The sidewall terminates at a frontal surface of the valve body with a conical bottom surface defining a flow aperture at its apex. A sealing shaft is fitted within the cavity and is enabled for lateral movement due to the eccentric sidewall. The sealing shaft provides at one end, a rubber seat sealing the flow aperture, and at the other end, a planar surface set at an off-normal angle. A fluid actuated vane extends away from the frontal surface of the valve body and is pivotally engaged with the planar surface of the sealing shaft so as to move the sealing shaft laterally, so as to uncover the aperture when the vane is forced out of a selected preliminary alignment with the sealing shaft.

Abstract: A hydraulic flow valve apparatus having a valve body providing a valve body cavity with an eccentric sidewall. The sidewall terminates at a frontal surface of the valve body with a conical bottom surface defining a flow aperture at its apex. A sealing shaft is fitted within the cavity and is enabled for lateral movement due to the eccentric sidewall. The sealing shaft provides at one end, a rubber seat sealing the flow aperture, and at the other end, a planar surface set at an off-normal angle. A fluid actuated vane extends away from the frontal surface of the valve body and is pivotally engaged with the planar surface of the sealing shaft so as to move the sealing shaft laterally, so as to uncover the aperture when the vane is forced out of a selected preliminary alignment with the sealing shaft.

Abstract: Position and angle are measured by a linear device having an elongate frame comprising a pair of parallel arms joined by a cross-arm, each of the arms terminating with an adjustable foot so that the device may be leveled, thereby establishing a level reference platform from which position and direction may be determined. A support bracket is adapted for rigid engagement with the elongate frame and is linearly positionable on it. A laser beam source is removably engagable with the support bracket for positioning a laser beam in a selected and known direction. The feet are spaced for clamping the T-bar sections of a dropped ceiling so as to enable the placement of further T-bars, roof joists and other structural members at selected angles. The arms provide parallel, spaced apart grooves for mounting the apparatus onto the T-bars.

Abstract: Position and angle are measured by a linear device having an elongate frame comprising a pair of parallel arms joined by a cross-arm, each of the arms terminating with an adjustable foot so that the device may be leveled, thereby establishing a level reference platform from which position and direction may be determined. A support bracket is adapted for rigid engagement with the elongate frame and is linearly positionable on it. A laser beam source is removably engagable with the support bracket for positioning a laser beam in a selected and known direction. The feet are spaced for clamping the T-bar sections of a dropped ceiling so as to enable the placement of further T-bars, roof joists and other structural members at selected angles. The arms provide parallel, spaced apart grooves for mounting the apparatus onto the T-bars.

Abstract: There is disclosed a method for improving the abrasion resistance of a cured rubber composition that is particularly suited for a tire tread compound comprising (a) dispersing from 1.0 phr to 30 phr of a C12-C36 alcohol and from 0.5 to 2.0 phr of sulfur throughout a dry isolated sulfur-vulcanizable rubber and (b) curing the rubber.

Abstract: In systems embodying the invention, circuitry responsive to first and second, complementary, input signals controls the application of the input signals to a positive signal integrator and to a negative signal integrator. When the amplitude of the input signals is greater than a predetermined value, the one of the two input signals which is positive relative to the other is applied to the positive signal integrator and the other one of the two input signals is applied to the negative signal integrator. When the amplitude of the input signals is smaller than a predetermined level, the circuitry causes the periodic application of the first input signal to the positive signal integrator and the second input signal to the negative signal integrator during one time interval, and the periodic application of the first input signal to the negative signal integrator and the second input signal to the positive signal integrator during a second, subsequent, time interval of similar duration as the one time interval.

Abstract: Signals generated by a knock sensor are coupled to an electronic network for amplifying and processing the output signals of the knock sensor. The electronic network includes a device for charging a storage capacitor to a potential which is a function of the amplitude of the knock sensor output signal. The storage capacitor is coupled to the input of an amplifier via a normally closed first switch. A detector for sensing any disconnection of the knock sensor from the electronic system produces a control signal indicative of a disconnect condition. The control signal is used to open the normally closed first switch and to cause the input of the amplifier to be clamped to a reference potential which lies outside the signal range normally produced across the storage capacitor whereby the output of the output of the amplifier is placed at a predetermined level indicative of a disconnect condition.

Abstract: A comparator circuit has first and second inputs and an output and includes means for operating the comparator in alternate autozero and comparator phases. During an autozero phase, the inputs of the comparator are clamped to a reference potential and during a compare phase, input signals are applied to the input of the comparator. Control signals are applied to the inputs of the comparator during a portion of the compare phase. The control signals determine the state of the comparator output when the input signals applied to the inputs of the comparator are below a predetermined level.

Abstract: A transconductance amplifier suitable for the input stage of a comparator with the capability of amplifying input signals with common mode voltage components in a range including the entirety of its operating voltage. Operation at one voltage extreme is accomplished by use of a long tailed pair connection of a pair of bulk modulated FETs with gates at the input terminals of the amplifier. Operation at the other voltage extreme is accomplished by the use of a pair of FETs in a source follower mode to drive common gate transistors of opposite polarity, the gates of the FETs also being connected to the input terminals of the amplifier. A common high impedance load for the comparator is connected to current mirrors of the drains of both pairs of FETs in the amplifier. The circuit may be implemented with bipolar transistors and additional amplification provided. Methods of comparing voltages are also disclosed.

Abstract: A Class D (audio) amplifier and method in which an input signal for the amplifier is pulse width modulated outside of the amplifier's feedback loop, and in which the pulse width modulated input signal and a pulsed signal from the feedback loop are summed in the feedback loop and fed back to the amplifier. The removal of the pulse width modulation stage and signal integration stage from the feedback loop improves distortion.

Abstract: A wet and dry refuse vacuum apparatus is disclosed. A vacuum canister includes a vacuum motor, and inlet assembly, and exhaust assembly including a liquid pump, an inlet control assembly, and an operating electrical circuit. Upon activation, the vacuum motor sucks air and liquid refuse into the canister from the inlet assembly. As liquid fills the canister, the electrical circuit activates the liquid pump which pumps the liquid from the canister out through the exhaust assembly. In the event that the liquid enters the canister at a higher rate than it leaves the canister, the inlet control assembly raises with the water level in the canister to restrict the amount of liquid that may enter through the inlet assembly. A floatation ball is arranged to block a floatation orifice near the vacuum generating motor in order to prevent the liquid from contacting the vacuum generating motor in the event that the liquid level nears the capacity of the canister.

Abstract: An apparatus which is used to enhance the capability of in situ drilling of holes in existing pipes or other conduits, or virtually any cylindrical object. The apparatus includes a mounting unit which rests upon the pipe to be drilled and a drill mounting apparatus. The drill mounting apparatus is removably mounted to the mounting unit. The drill mounting apparatus is adapted to receive and position a drilling device which forms a hole in the pipe or the like.

Abstract: Circuit for indicating when a voltage indicative of a condition, such as the presence of smoke, changes to a value outside of a given voltage range. It includes an oscillator which oscillates in response to a value of voltage within said range and which stops oscillating when the voltage changes to a value outside of said range. A circuit coupled to said oscillator sounds an alarm when the oscillations cease.

Abstract: The input stage of an amplifier includes two input terminals to which are connected the gates of two, differentially connected, IGFETs protected by two diodes connected back-to-back (in series) between the gates. The amplifier also includes means for applying an external signal source to one input terminal, means for shorting the diode connected to the other input terminal, and means for negatively feeding back the output of the amplifier to its input. This maintains the potential difference across the diode connected to the input terminal to which the external signal source is connected close to zero volt thereby substantially eliminating any leakage current through it.

Abstract: A circuit is disclosed for detecting ground faults and neutral faults and for providing power interruption in response thereto. The circuit monitors the current flow in the line and neutral conductors and provides a signal to a power interruption circuit in the event that a ground fault or a neutral fault condition is detected. In addition, a signal having a certain frequency is generated and coupled on the neutral line to enhance the probability of detecting neutral faults.