Abstract: Parallel switches arranged to transfer power between an AC power source and a load may be individually operated during different portions of the AC waveform. In some embodiments, the switches may be operated during alternate cycles of the waveform to cause the individual switches to sequentially conduct the entire load current.

Abstract: A method includes selectively applying full cycles of AC power to a load. The cycles may have first and second states such as full on and full off states. The cycles may be arranged in groups in a pattern. The pattern may have a length that is shorter than a perceptible response time of the load. Different patterns may be used for different power levels.

Abstract: The present invention includes a device for providing connections to a plurality of inputs of a circuit to be tested. A computer stores test vectors comprising data representing stimulus signals to be applied to the circuit and data representing response signals to be sensed from the circuit. The stored test vectors are applied through a driver associated with each input of the circuit to be tested. The driver has an output capable of assuming a high state, a low state or a floating state. A driver control causes the driver to assume a high or low output state in response to data representing stimulus signals and causes the driver output to assume a floating state in response to data representing response signals. Response signals from the device to be tested are compared to the data representing response signals to determine the occurrence of a fault.

Abstract: The first monostable multivibrator of a series connected pair of monostable multivibrators is responsive to each break interval of input dial pulses for establishing a fixed time delay after which the second multivibrator initiates a corrected break interval and starts a first timing capacitor thereof charging at a rate set by a fixed time constant. Each input break interval also causes a capacitor of a second timing circuit to start discharging at a rate set by another fixed time constant, the time that the second capacitor starts discharging being a function of the pulse repetition frequency of input dial pulses. When the charge voltages on the two capacitors are the same values, the output of a comparator resets the second multivibrator to terminate an output break interval so as to cause corrected dial pulses in the output thereof to have a constant percent break.

Abstract: A decoded PAM input signal is coupled through a first polarity switch (which for one polarity of a polarity signal is closed) to the positive input line of a differential operational amplifier and through the series combination of a second polarity switch (which is open for the one polarity) and an input resistor to the negative input line of the differential amplifier. The positive input line is resistively connected to ground through a first bias resistor and is also connected to ground through the series combination of a second bias resistor and a third polarity switch which is also open for the one polarity. A feedback resistor is connected between the output line and the negative input line of the amplifier.