Abstract: The present invention relates to a power supply modulator for a radio transmitter having apportioned input impedance and buffered switching of power modules. A series arrangement of power supply modules, conventionally disposed in a diode cascade, includes individual inductors to apportion the input impedance of the switching power supplies. The switching sequence of the power supplies is controlled by a FIFO buffer, with the sequentially adjacent power supplies being disposed physically remote so that current transients and thermal loads are more uniformly distributed.

Abstract: The present invention involves a programmable microprocessor based controller having the capacity to store multiple operational instruction sets for independently controlling system components. The invention further involves a distributed intelligence network of such programmable controllers having the capability to interface with one another, Host computers, and system control components to provide system-wide automation for simultaneously monitoring and controlling video, audio, and electro-mechanically operated equipment. The programmable controller accepts analog and digital inputs and provides a wide range of user defined control functionality through its analog and digital outputs and its many external connections. The controller can support one and possibly two communication buses, depending upon the application, upon which a plurality of system components may be connected to each.

Abstract: An audio system includes a light sensitive switch connected to a microphone. Activation of the microphone operates the switch, thereby indicating that the microphone is in use. When the user turns the microphone on, a voltage is applied across a light emitting diode which causes the diode to emit light. The light activates the light sensitive switch which is connected to the remainder of the audio system. The system interprets activation of the light sensitive switch as an indication that the microphone is in use and responds accordingly.

Abstract: The present invention relates to a power supply modulator for a radio transmitter having apportioned input impedance and buffered switching of power modules. A series arrangement of power supply modules, conventionally disposed in a diode cascade, includes individual inductors to apportion the input impedance of the switching power supplies. The switching sequence of the power supplies is controlled by a FIFO buffer, with the sequentially adjacent power supplies being disposed physically remote so that current transients and thermal loads are more uniformly distributed.

Abstract: A power converter includes a pair of switches, each of the switches being connected between positive and negative constant DC voltage sources and a common output node which is connected to a load. A modulator opens and closes the switches in a sequence in which the electrical current controlled by the switches are in opposition to one another at the common output node, and are summed at the output node. The modulator includes a triangle wave generator and comparators which are connected to an error amplifier to provide a bearing switching voltage to the comparators. The comparators switch the control switches in response to the triangle wave generated by the triangle wave generator increasing above and decreasing below the reference levels. Underlap and overlap of the converter is controlled by varying of the DC bias level of the triangle wave.

Abstract: A power converter which includes a bridged power amplifier powered from a sole or single DC input power source through a plurality of parallel connected PWM buck converters. The converters are modulated with reference signals which operate in time alternation such that in any conversion cycle there exists a plurality of modulating wave forms which are identical except for their time delays and which are evenly spaced in time over a single conversion cycle. A feedback control amplifier compares the voltage output of the parallel connected converters through the magnitude of the amplifier's required supply voltage and drives the modulating components of the circuit to control the switching duty cycle of each of the individual PWM converters.

Abstract: The present invention involves an amplifier control module for an amplifier system including the addition of firmware to allow stand alone operation and to independently perform desirable functions to enhance amplifier and system operation. The system includes a Host computer connected through an interface device to the control module to send and receive serial data. An operator can set parameters and define control module responses with a Host computer. Once the parameters have been set, the control module can be severed from the system and will operate as a stand alone controller according to the firmware. The firmware includes instructions for implementing smooth output limiting (SOL), automatic standby, short detection, enhanced output device emulator protection (ODEP) conservation, and interrupt driven reporting.

Abstract: This invention employs timing circuitry for each voltage source in a multilevel power supply for an amplifier to control the change in voltage outputted from the associated voltage source over time or slew rate when that voltage source is switched on or off preventing large instantaneous voltage increases at the input of the amplifier from occurring when a combination of the voltage sources supplying the amplifier is switched to a different combination upon the output voltage of the amplifier changing.

Abstract: The present invention relates to a power supply modulator for a radio transmitter having apportioned input impedance and buffered switching of power modules. A series arrangement of power supply modules, conventionally disposed in a diode cascade, includes individual inductors to apportion the input impedance of the switching power supplies. The switching sequence of the power supplies is controlled by a FIFO buffer, with the sequentially adjacent power supplies being disposed physically remote so that current transients and thermal loads are more uniformly distributed.

Abstract: A multiplexer for mixing multiple audio inputs into a plurality of summed audio outputs in which computer-controlled sensors are associated with the amplifier components of the multiplexer for specific monitoring the voice levels and in association with the volume controls maintains the voice levels within selected parameters.

Abstract: A sixteen level power supply including four voltage sources having stepped voltage values. The voltage sources are controlled by an electronic switch assembly and may be switched into series between the positive and negative output voltage terminals. The switches are controlled by a controller circuit which monitors voltage available at each voltage source in comparison to a demand signal. The controller output a digital control bit to activate each switch.

Abstract: An amplifier selector for use with a MRI machine having stacked amplifiers. The selector includes a switch assembly carried by each amplifier and controlled by a central controller. Each switch assembly includes a motor for rotating a plurality of switch plates to various predetermined stations. The stations connect the input and output terminals of the slave amplifier to either the X, Y or Z axis of the MRI machine. A fourth station is included to define an off line condition for the amplifier.

Abstract: A sixteen level power supply including four voltage sources having stepped voltage values. The voltage sources are controlled by an electronic switch assembly and may be switched into series between the positive and negative output voltage terminals. The switches are controlled by a controller circuit which monitors voltage available at each voltage source in comparison to a demand signal. The controller output a digital control bit to activate each switch.

Abstract: A control system for an audio amplifier including a control module interconnected by an edge connector to an amplifier to monitor status signals and the audio input and output signals from the amplifier. The control module passes serial data to an interface which interconnects the plurality of control modules and amplifiers to a single host computer. The host computer receives data from the interface and transmits instructions to the interface for routing to the specific amplifier control module to control the amplifier's gain along with other audio functions and a remote power supply. The control module can be set to run in a stand alone mode to regulate the amplifiers thermal dynamic response to the audio signals and prevent thermal clipping.

Abstract: A method for the determination and display of signal arrival time, intensity, and direction for use with time domain measurements. The method may be implemented by either hardware or by software and includes obtaining at least four separate time domain measurement, such as energy time curves (ETCs), at ninety degree intervals on a horizontal plane. Opposing ETCs are differenced to obtain X and Y Cartesian components. For display in a polar format to illustrate the direction of arrival the X and Y components are converted into an angular value. The angular value determining the theta angle and either the time of arrival or intensity expressed in X and Y components establish the polar vector length. To display a three dimensional space two more ETCs are obtained in a vertical plane and correlated in the manner described above.

Abstract: A switch connected between two voltage sources and responsive to a sensing circuit. The switch includes a transistor which operates to interchange the electrical connection of the two voltage sources from parallel to series upon the sensing circuit signals the need for more voltage. The two sources are normally in parallel to increase the cost efficiency and energy efficiency of the amplifier and power supply.

Abstract: A directional microphone having an acoustic damping washer positioned about the microphone cartridge adjacent the microphone rear sound entry.

Abstract: A method of fault sensing for a power amplifier having direct coupled power stages with normally mutually exclusive current flow in which the alternating current output is simultaneously sensed and, when a fault is detected, is ANDed. A power reduction to the amplifier is initiated when the ANDed output exists for a selected period of time.

Abstract: A differential microphone which includes a plate positioned between and spanning the sound-receiving opening of the microphone. Carried by the plate is a transducer having opposed sound entries surrounded by one or more bores which extend through the plate. The plate serves to delay sound reception at one transducer sound entry.