Zenith Radio Corporation

Robert R Podowski

Richard W Citta

Johnny Collins

A battery powered portable acoustic transmitter comprises a plurality of single-pole, momentary contact switches, a type 555 pulse producing integrated circuit chip, and an electroacoustic transducer and matching tuning coil. An RC timing circuit includes a plurality of resistors selectively connectable in the timing circuit by the switches to vary the pulse output frequency. A transistor output circuit amplifies the pulses for driving the transducer. A plurality of diodes supply power to the chip and the transistor output circuit whenever a switch is activated. The integrated circuit chip, resistors, diodes and transistor are part of an active thick film circuit.

Signal transmitter using an active thick film substrate

An electronic remote control transmitter employs a two transistor cascade oscillator having positive and negative feedback loops. The oscillator voltage is supplied through a switch assembly containing a plurality of momentary contact switches to a pair of voltage dividers supplying signal voltages in predetermined ratios to a two branch circuit in the negative feedback loop. One branch contains an inductor and the second branch a capacitor. Closure of any switch completes the DC circuits for the transistors. Signal voltage is supplied to the branches to produce a minimum amplitude, zero phase shift condition which establishes oscillation at that predetermined frequency. The output of the oscillator is amplified by a third transistor and supplied to an ultrasonic transducer for generating acoustical control signals.

Electric remote control transmitter

A wireless remote control system has a transducer coupled to a sampling first counter for counting the frequency of incoming signals. A portion of the count distinguishes among various control signal frequencies and is supplied to a memory and a comparator. A second counter counts the number of identical comparisons of present and immediately preceding measurements, and is reset when a non-identical comparison is detected. The memory supplies the stored portion of the count to a decoder which is disabled by the second counter until a predetermined number of identical frequency comparisons have been determined, which provides noise immunity. The decoder is coupled to utilization means to activate the control function corresponding to the frequency of the control signal.

Digital remote control system with signal verification

A broadcast receiver has a reversible binary counter having its output coupled to a digital-to-analog converter which translates the counter's binary coded output signal to a control voltage and applies it to a voltage controllable circuit means. A local source of clock pulses is selectively coupled to the counter by a pair of operator actuated switches to preferentially alter the counter output signal. The binary coded counter output signals are coupled to a non-volatile memory by read/write means for storage during periods of receiver deactivation and reimposed on the counter during subsequent activation of the receiver. Receiver activation and deactivation transitions are detected by voltage sensing means which are coupled to the read/write means and are responsive to changes in the receiver operating potential. Preset means comprising a non-volatile, non-erasable memory and selector switches permit resetting the counter to a predetermined binary data configuration.

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Elmhurst, IL, United States of America

Robert R Podowski