Abstract: The present disclosure provides a pulse generator which generates a pulse train by mixing pulses of a first clock having a first frequency, with pulses of a second clock having a second frequency. Over a predefined time period, the combination of pulses results in a pulse train having an effective frequency which is between the first and second frequencies. A multiplexer is used to select which of the first and second clocks should be provided to the output. Depending on the desired target frequency, the multiplexer is controlled to mix differing amounts of pulses from the first and second clocks. A multiplexer is controlled by a control signal, which is generated using combinatorial logic using the first clock as an input. The pulse generator may be used, for example, as a clock for a charge pump.

Abstract: The present disclosure provides a pulse generator which generates a pulse train by mixing pulses of a first clock having a first frequency, with pulses of a second clock having a second frequency. Over a predefined time period, the combination of pulses results in a pulse train having an effective frequency which is between the first and second frequencies. A multiplexer is used to select which of the first and second clocks should be provided to the output. Depending on the desired target frequency, the multiplexer is controlled to mix differing amounts of pulses from the first and second clocks. A multiplexer is controlled by a control signal, which is generated using combinatorial logic using the first clock as an input. The pulse generator may be used, for example, as a clock for a charge pump.

Abstract: A method and apparatus for automatic resonance detection is disclosed for a motor-driven mechanical system such as a voice coil motor (VCM) in which a resonance detector and driver are provided. The automatic resonance detector is implemented on the same integrated circuit as the driver, and dynamically determines the natural resonant frequency of the VCM driven by the driver. The resonant frequency is determined by measuring the back electromotive force (BEMF) of the VCM, detecting the slope of the BEMF signal, and determining the resonant frequency from the slope of the BEMF signal.

Abstract: A method and apparatus for automatic resonance detection is disclosed for a motor-driven mechanical system such as a voice coil motor (VCM) in which a resonance detector and driver are provided. The automatic resonance detector may be implemented on the same integrated circuit as the driver, and dynamically determines the natural resonant frequency of the VCM driven by the driver. The resonant frequency is determined by measuring the back electromotive force (BEMF) of the VCM, detecting the slope of the BEMF signal, and determining the resonant frequency from the slope of the BEMF signal.

Abstract: An explosion-proof emergency light. The emergency light includes an explosion-proof housing containing a rechargeable battery, a sealed-beam light and emergency electronics for providing a charging current for the battery and for connecting the sealed-beam light to the battery upon loss of AC line voltage. Access is provided to the interior of the explosion-proof emergency light through a circular cover containing an explosion-proof glass window through which emergency illumination is provided. The sealed-beam light is located eccentrically with respect to the glass window; and indicator lights for denoting the charge state of the rechargeable battery and the presence of AC current are mounted above the sealed-beam light, both being disposed in the cresent-shaped area formed by the aforesaid eccentric mounting, so as to be visible from the exterior of the explosion-proof emergency lamp.

Abstract: A battery charger circuit for providing a charging current to a rechargeable battery from AC line voltage. The charger circuit is especially adapted for use in an emergency light and includes circuitry to provide automatic charging current shut-off when the battery is fully charged. Failure of AC power is detected by the charger circuit, and current is applied to an emergency lamp in response to such failure. Circuitry is included for monitoring the charge state of the battery and for interrupting discharge current to the lamp from the battery when the charge state falls below a predetermined limit. Provision is included for use of the battery charger circuit in a portable lantern configuration.

Abstract: A connector assembly for rechargeable battery-operated power supplies requiring a watertight housing. Such a connector is usable, for example, in conjunction with a waterproof housing for a hand-carried, rechargeable floodlight. The connector assembly incorporates a male connector member affixed to the exterior of the housing for mating with a female connector via which power may be supplied to recharge a battery maintained within the housing. Vents which permit gases generated by the charging operation to escape from the housing are located interior to the periphery of said connector assembly. When the battery is not being recharged, the connector assembly is covered by a watertight cap, thereby closing the vents and protecting the male connector member. A pilot lamp charge indicator is provided, and the cap provides protection against injury thereto.

Abstract: An emergency table lamp which functions as an ordinary table lamp during non-emergency conditions and which provides emergency illumination upon loss of A/C power. The emergency table lamp is constructed so as to be aesthetically appealing while still allowing access to the emergency lighting electronics. A battery and charger assembly having spring terminals are held in place within the lamp body and electronically connected by means of an insulating contact plate secured within the lamp body and having appropriate bus bars for providing the required electrical connection. The contact plate allows independent removal of the battery and charger assembly for repair or replacement.

Abstract: A high reliability universal electrical swivel fabricated of insulative material virtually impervious to moisture or corrosive acid or alkaline vapors and having substantial flexural elasticity provides a conduit for an electrical conductor rotatable and tiltable about orthogonal axes. The swivel is adapted to retain its fixed position notwithstanding severe vibration and shock. Novel design minimizes stress on the internal conductor and its insulation thus minimizing the possibility of internal short circuits. The swivel components are especially adapted for economical mass manufacture and assembly.