Motorola Corporation

Thomas R Klaus

Sharada Raghuram

Frank Robert Skutta

Gary J Pregont

Les Updegrove

Stephen J Milligan

John S Strauss

A universal power transformer (101) is for connection to an AC power source and produces a regulated DC voltage at an output thereof. The power transformer includes a power transformer housing (102) with a recess (114). A universal power converter circuit (313) is positioned in the housing. Connector prongs (108, 110) are electrically coupled to the circuit and are movably carried on the housing at a position adjacent the recess. The prongs move between an outwardly extending position, projecting from the housing for connection to a first type of power supply connector, and a retracted position, extending into the recess for storage during transport of the power transformer and for connection to an adapter (103-106) positioned in the recess, to connect to a second type of power supply connector.

Power transformer

A method of controlling a receiver's on-time (313). The radio receiver (109) receives radio frequency signals (309) of a predetermined duration (305) at an interval having a predetermined time period (301). The method varies the receiver's on-time (415, 417) until the data detector (205) is on the verge of failing to detect all of the data.

Receiver controller method and apparatus

A radio-on timer and transmission-on timer of a cellular telephone (100) provide an accurate record of the total amount of time since manufacture that the cellular telephone (100) and its transmitter (160), respectively, have been turned on for the purpose of measuring the in-field reliability thereof. The cellular telephone (100) includes a processor (110) that is responsive an interrupt signal (117) for incrementing and storing an interrupt timer, the radio-on timer and the transmission-on timer in a volatile memory 114. When the processor (110) senses that power has been switched off, the processor (110) reads out from the volatile memory (114) the radio-on timer and transmission-on timer, reads out from the non-volatile memory (112) the previously stored radio-on timer and transmission-on timer, adds them together and stores the summed radio-on timer and transmission-on timer back in the non-volatile memory (112). The unique radio-on and transmission-on timers of the present invention may be advantageously utilized in any radio including a transmitter.

Cellular telephone with transmission-on and radio-on timers

A synthesizer radio frequency (RF) signal receiver (FIG. 1) for single sideband radios is described that can eliminate interference due to internally generated spurious signals, commonly referred to as 'whistler spurs'. The unique receiver includes first and second mixers (102 and 106), which are intercoupled by a 75 mHz crystal filter (104) having a 20 kHz passband, and which are each coupled to signals from voltage controlled oscillators (120 and 140). The first IF frequency provided by the first mixer (102) varies about 75 mHz, and the second IF frequency provided by the second mixer (106) is fixed at 11.4 mHz. The second mixer (106) is coupled to 11.4 mHz stages (108) which have a 2.7 kHz passband. The 11.4 mHz stages (108) are followed by another mixer (110) and audio stages (112) for demodulating audio signals from the received RF signal, which are then applied to a speaker (114). The frequency of the VCO (120) coupled to the first mixer (102) can be varied by changing the divisor N of a programmable divider (123), and the frequency of the VCO (140) coupled to the second mixer (106) likewise can be varied by changing the divisor M of a programmable divider (133). When interference due to a whistler spur is present, activation of an IF pushbutton (160) enables a microcomputer (170), which changes divisors N and M for varying the frequencies of the two VCO's (120 and 140) by a multiple of 3.2 kHz, which in turn shifts the first IF frequency by 3.2 kHz. The frequency change also shifts the whistler spur outside of the 2.7 kHz passband of the 11.4 mHz stages (108) and greatly attenuates it. If the whistler spur is not sufficiently attenuated, the IF pushbutton (160) can be activated a second time.

Method and apparatus for eliminating interference due to spurious

A plurality of resistors are series coupled with the free ends forming the end points of the potentiometer. A plurality of electronic switches have each of their inputs coupled to a predetermined point in the resistor array. The output from the switches are connected in common, thus forming the tap to the potentiometer. Activation of the switches is determined by control logic comprising an up/down counter, the outputs from which couple to the switches, an astable multivibrator for incrementing the counter and gating circuitry for selectively coupling the astable to the counter. The control logic is arranged to respond to received command signals for causing the tap to sequentially increment towards either end of the pot and to stop incrementing at a desired point. Further, the control logic causes the sequential tap incrementing to reverse once the tap reaches either end point of the pot.

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Palatine, IL, United States of America

Thomas R Klaus