Abstract: A hearing protection system is provided. The hearing protection system has a first active hearing protection system. The first active hearing protection system is level-dependent. The hearing protection system also has a second active hearing protection system. The second active hearing protection system is level-dependent. Each of the first and second active hearing protection systems are configured to operate in an independent mode and a dual-protection mode. A dual-protection mode level dependent function of the second active hearing protection system is different than an independent mode level dependent function.

Abstract: A hearing protection system is provided. The hearing protection system has a first active hearing protection system. The first active hearing protection system is level-dependent. The hearing protection system also has a second active hearing protection system. The second active hearing protection system is level-dependent. Each of the first and second active hearing protection systems are configured to operate in an independent mode and a dual-protection mode. A dual-protection mode level dependent function of the second active hearing protection system is different than an independent mode level dependent function.

Abstract: The present application relates to a battery-powered electronic device, such as an electronic hearing protector, with switchable electrical contacts. The device includes a housing enclosing the battery and an electronics assembly. The electronics assembly is powered by the battery, and the electronics assembly comprises a processor controlled by updatable software. The device further includes a first electrical contact that is a ground line; a second electrical contact that is a data programming line in a first state, and that is a charging voltage line in a second state; and a third electrical contact that is a clock line in a first state, and that is a charge enable line in the second state. The first, second and third electrical contacts are accessible from outside the housing. A switch enclosed by the housing changes the second electrical contact between the first state and the second state.

Abstract: The present application relates to a battery-powered electronic device, such as an electronic hearing protector, with switchable electrical contacts. The device includes a housing enclosing the battery and an electronics assembly. The electronics assembly is powered by the battery, and the electronics assembly comprises a processor controlled by updatable software. The device further includes a first electrical contact that is a ground line; a second electrical contact that is a data programming line in a first state, and that is a charging voltage line in a second state; and a third electrical contact that is a clock line in a first state, and that is a charge enable line in the second state. The first, second and third electrical contacts are accessible from outside the housing. A switch enclosed by the housing changes the second electrical contact between the first state and the second state.

Abstract: The present application relates to a battery-powered electronic device, such as an electronic hearing protector, with switchable electrical contacts. The device includes a housing enclosing the battery and an electronics assembly. The electronics assembly is powered by the battery, and the electronics assembly comprises a processor controlled by updatable software. The device further includes a first electrical contact that is a ground line; a second electrical contact that is a data programming line in a first state, and that is a charging voltage line in a second state; and a third electrical contact that is a clock line in a first state, and that is a charge enable line in the second state. The first, second and third electrical contacts are accessible from outside the housing. A switch enclosed by the housing changes the second electrical contact between the first state and the second state.

Abstract: The present application relates to a battery-powered electronic device, such as an electronic hearing protector, with switchable electrical contacts. The device includes a housing enclosing the battery and an electronics assembly. The electronics assembly is powered by the battery, and the electronics assembly comprises a processor controlled by updatable software. The device further includes a first electrical contact that is a ground line; a second electrical contact that is a data programming line in a first state, and that is a charging voltage line in a second state; and a third electrical contact that is a clock line in a first state, and that is a charge enable line in the second state. The first, second and third electrical contacts are accessible from outside the housing. A switch enclosed by the housing changes the second electrical contact between the first state and the second state.

Abstract: A battery-powered electronic device, such as an electronic hearing protector (100) includes a housing (113) enclosing the battery and an electronics assembly powered by the battery, the electronics assembly comprises a processor controlled by updatable software. The device further includes a first electrical contact (119a) that is a ground line; a second electrical contact (119b) that is a data programming line in a first state, and that is a charging voltage line in a second state; and a third electrical contact (119c) that is a clock line in a first state, and that is a charge enable line in the second state. The first, second and third electrical contacts (119a-c) are accessible from outside the housing (113). A switch enclosed by the housing (113) changes the second electrical contact (119b) between the first state and the second state.

Abstract: A battery-powered electronic device, such as an electronic hearing protector (100) includes a housing (113) enclosing the battery and an electronics assembly powered by the battery, the electronics assembly comprises a processor controlled by updatable software. The device further includes a first electrical contact (119a) that is a ground line; a second electrical contact (119b) that is a data programming line in a first state, and that is a charging voltage line in a second state; and a third electrical contact (119c) that is a clock line in a first state, and that is a charge enable line in the second state. The first, second and third electrical contacts (119a-c) are accessible from outside the housing (113). A switch enclosed by the housing (113) changes the second electrical contact (119b) between the first state and the second state.

Abstract: An integrated circuit (IC) includes circuitry for generating a clock signal during both a normal mode of operation and a test mode of operation. During the normal mode, an input clock signal is delayed via a skew corrector. In test mode, an input test clock signal bypasses the skew corrector via a clock signal source selector. The clock signal source selector is controlled automatically by a mode detector that responds to the input clock signals to determine the mode of operation of the IC.

Abstract: An expander circuit for decoding audio signals which were encoded in accordance with the BTSC multichannel sound system standard including DBX commanding is presented. A wideband expander circuit is utilized and a DBX expander can be accommodated. The wideband expander circuit is provided with a signal path having an input LPF (low pass filter), a stereo difference signal (L-R) demodulator, a second LPF, and a voltage controlled amplifier (VCA), the gain of which is controlled by a control signal derived from the demodulated difference signal which has been operated on by a bandpass filter (BPF) and an integrating peak detector. The output of the VCA is provided to a deemphasis network before being fed to a decoder matrix for combining with the sum stereo signal (L+R) for reconstructing the original L and R signals.

Abstract: An expander circuit for decoding audio signals which were encoded in accordance with the BTSC multichannel sound system standard including DBX companding is presented. A wideband expander circuit is utilized and a DBX expander can be accommodated. The wideband expander circuit is provided with a signal path having an input LPF (low pass filter), a stereo difference signal (L-R) demodulator, a second LPF, and a voltage controlled amplifier (VCA), the gain of which is controlled by a control signal derived from the demodulated difference signal which has been operated on by a bandpass filter (BPF) and an integrating peak detector. The output of the VCA is provided to a deemphasis network before being fed to a decoder matrix for combining with the sum stereo signal (L+R) for reconstructing the original L and R signals.

Abstract: Clock phase shifting circuitry includes a cascade connection of inverting amplifiers for generating a plurality of relatively delayed clock signals. Buffer amplifiers couple alternate ones of the inverting amplifiers to a clock phase selection circuit for providing a desired one of said plurality of delayed clock signals. A capacitor is coupled between the output of each inverting amplifier and a point of constant potential. Respective circuits, having an input impedance which emulates the input impedance of the buffer amplifiers, are coupled to the output connections of the inverting amplifiers located between said alternate inverting amplifiers.

Abstract: In apparatus including a number of functional elements coupled to a common supply bus, certain of the elements may draw time varying supply current related to signal being processed. Supply current compensation circuitry responsive to signal processed by such elements is included to draw equal and opposite time varying supply current to maintain the total supply current constant and thereby to limit localized supply potentials variation. Exemplary compensation circuitry for an amplifier includes a transistor coupled between the supply busses and controlled by signal potential from the amplifier to draw supply current proportional to the signal applied to the amplifier, which supply current is opposite in phase to supply current drawn by the amplifier.

Abstract: A television receiver includes an audio signal processing arrangement for expanding a second audio program (SAP) signal compressed in accordance with the "dbx" system in a relatively simple manner. The signal processing arrangement includes a first filter for providing a first amount of deemphasis. A controllable gain amplifier has its input coupled to the filter and its gain controlled by a filtered signal representative of its input signal. A second filter at the amplifier output provides a second amount of deemphasis.

Abstract: A television receiver has provisions for a second audio program (SAP) and an indication for signifying when the SAP is present and a muting circuit for muting the SAP, both in response to the output signal of a SAP detector. A filter capacitor is coupled to the detector output to prevent flicker of the indicator due to noise. To prevent the filter capacitor from incorrectly maintaining an indication of the presence of a SAP, thereby preventing proper SAP muting, when a new channel is selected, channel change signal causes a semiconductor switch to discharge the filter capacitor.