Motorola Corporation

Brian K Terry

Christopher A Myers

Scott M Engstrom

Wei L Tan

Steven D Hall

Robert J McDermott

A collector-injector mixer circuit (100) has a first differential pair of transistors having first and second transistors (102, 104) whose emitters are connected to a common first emitter terminal (110), and a second differential pair of transistors having third and fourth transistors (106, 108) whose emitters are connected to a common second emitter terminal (112). The bases of the first and fourth transistors (102, 108) are coupled to a common first base terminal (114) and the bases of the second and third transistors (104, 106) are coupled to a common second base terminal (116) between which a mixing signal is applied. A third differential pair of transistors have fifth and sixth transistors (124, 126) wherein collector (130, 132) of the fifth transistor (124) and sixth transistor (126) receive an input signal, an emitter of the fifth and sixth transistors (124, 126) are coupled through resistors (146, 148) to ground, and bases of the fifth and sixth transistors are coupled to a reference current circuit (150).

Collector-injection mixer with radio frequency signal applied to

The programmable electronic device, such as a radio, includes a memory for storing program information. A controller, such as a microprocessor, is connected to the memory for programming and reading the memory. A keypad is provided for data entry and is connected to the microprocessor. A magnetic switch, such as a Hall effect switch, is located within the radio and controls the program enable line of the microprocessor. The Hall effect switch is actuated by an externally supplied magnetic field for enabling programming of the memory of the radio.

Programmable electronic device

A battery charger includes a first charger for providing a first battery charging current and a second charger for providing a second battery charging current. A switch is provided for manually actuating the second charger. A timer times the second charger cycle. The timer is used to initiate the discontinuation of operation of the second charger. When the second charger is operating, the timer is inhibited from being reset. When the first charger discontinues supplying a charging current, the battery charger is conditioned to again permit actuation of the switch to reset the timer and allow operation of the second charger.

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Coral Springs, FL, United States of America

Brian K Terry