Abstract: A tool string includes a perforating gun, a first electrical connector defining a receptacle and includes a first electrical contact positioned in the receptacle, and a sub including a sub housing including first end, a second end opposite the first end, and a central passage extending between the first end and the second end, and a bulkhead connector positionable in the central passage to form a pressure barrier along the central passage, the bulkhead connector including an outer housing defining a radially outer periphery of the bulkhead connector, and a second electrical contact positioned along the outer periphery of the bulkhead connector and configured to establish radially directed electrical contact with the first electrical contact of the first electrical connector irrespective of the angular orientation of the second electrical contact relative to the first electrical contact.

Abstract: A method for producing a tandem sub for a perforating gun system includes positioning an electrically conductive signal bar in a central passage of a tubular housing of the tandem sub, and injecting a mold material into an annulus formed between an outer surface of the signal bar and an inner surface of the tubular housing that sealably adheres to both the signal bar and the tubular housing.

Abstract: A buck-boost converter with a switch controller may cause switches A, B, C, and/or D to cyclically close such that switches B and C are closed during at least one interval of each cycle during both the buck and boost modes of operation. The switch controller may in addition or instead cause switches A, B, C, and/or D to cyclically close based on a control signal such that switches A and D are closed during an interval of each cycle and such that these intervals are never both simultaneously modulated by a small change in the control signal during any mode of operation.

Abstract: A buck-boost converter with a switch controller may cause switches A, B, C, and/or D to cyclically close such that switches B and C are closed during at least one interval of each cycle during both the buck and boost modes of operation. The switch controller may in addition or instead cause switches A, B, C, and/or D to cyclically close based on a control signal such that switches A and D are closed during an interval of each cycle and such that these intervals are never both simultaneously modulated by a small change in the control signal during any mode of operation.

Abstract: Voltage regulators and methods for regulating voltages are disclosed. A switching circuit with an inductor and a plurality of switches may be used to produce a regulated voltage from an unregulated voltage source. A control circuit may be used to monitor the voltages at the input and output of the voltage regulator, and operate the switches in either a buck, boost, or buck-boost mode depending on the relationship between the voltages at the input and output of the voltage regulator.

Abstract: A control circuit for a piezo transformer based power supply includes oscillator circuitry, drive circuitry, sense circuitry, and feedback circuitry collectively operating to regulate an operational parameter of the supply, such as the current supplied to a cold cathode fluorescent lamp (CCFL). The feedback circuitry includes initialization circuitry that establishes an initial value of an oscillator control signal corresponding to an initial operating frequency, and thereafter permits the feedback circuitry to gradually drive the oscillator control signal to a normal operating value such that the operating frequency is swept from the initial operating frequency to a normal operating frequency. When controlling the power supplied to a CCFL, the initial operating frequency is preferably a maximum frequency of the oscillator, and the operating frequency is swept downward so as to pass through the frequency at which the lamp “strikes”, or begins conduction, and thereafter into regulation.

Abstract: A control circuit for a piezo transformer based power supply includes oscillator circuitry, drive circuitry, sense circuitry, and feedback circuitry collectively operating to regulate an operational parameter of the supply, such as the current supplied to a cold cathode fluorescent lamp (CCFL). The feedback circuitry includes initialization circuitry that establishes an initial value of an oscillator control signal corresponding to an initial operating frequency, and thereafter permits the feedback circuitry to gradually drive the oscillator control signal to a normal operating value such that the operating frequency is swept from the initial operating frequency to a normal operating frequency. When controlling the power supplied to a CCFL, the initial operating frequency is preferably a maximum frequency of the oscillator, and the operating frequency is swept downward so as to pass through the frequency at which the lamp “strikes”, or begins conduction, and thereafter into regulation.

Abstract: A multi-channel interleaved power converter includes first and second per-channel conversion circuits, each including a pulse width modulator (PWM), a driver PWM, an output inductor carrying load current, and a current controlled current source (CCCS) coupled to sense the inductor current. The inductors of the different channels are coupled in common to an output node of the power converter. Summing circuitry is operative (i) to subtract the output current of the second channel CCCS from the output current of the first channel CCCS, (ii) to convert the difference current into an offset, and (iii) to apply the offset to a first PWM control signal to generate a second PWM control signal for the second channel. The PWM control signals cause respective currents to be established in the inductors of the different channels according to a predetermined desired current relationship, such as equality.