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公开(公告)号：US3883807A
公开(公告)日：1975-05-13
申请号：US47466574
申请日：1974-05-30
Applicant: MOTOROLA INC
Inventor： ALBERKRACK JADE H
CPC classification number: H03J5/0281 , H03L7/185
Abstract: A phase-locked loop tuning system for a television receiver tunes the VHF and UHF local oscillators to the required frequency for the channel selected by sampling the output frequencies of the VHF and UHF local oscillators, pre-scaling these output frequencies to a different frequency range under the control of selected gated offset oscillators to produce a signal which is divided in a programmable divide-by-N counter, wherein is the desired channel number. The counter output is compared with a reference frequency to produce the control voltage for the tuner local oscillators to lock them on the proper frequency for the selected channel.
Abstract translation: 用于电视接收机的锁相环调谐系统通过对VHF和UHF本地振荡器的输出频率进行采样选择的信道将VHF和UHF本地振荡器调谐到所需频率，将这些输出频率预分频到不同的频率范围 在所选择的门控偏移振荡器的控制下产生被分为可编程的除N计数器的信号，其中是所需的信道号。 将计数器输出与参考频率进行比较，以产生调谐器本地振荡器的控制电压，将其锁定在所选通道的适当频率上。
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公开(公告)号：AU3100099A
公开(公告)日：2000-07-03
申请号：AU3100099
申请日：1999-03-18
Applicant: MOTOROLA INC
Inventor： HALL JEFFERSON W , ALBERKRACK JADE H
Abstract: A power converter circuit (23) and a method for controlling current in a transformer (16). The power converter circuit (23) includes a controller circuit (60), a duty cycle detector circuit (61), a soft start circuit (62), and a switch (63). The switch (63) controls the current in the transformer (16). The controller circuit (60) cooperates with the soft start circuit (62) to alter the duty cycle of the switch (63). During initial start-up, the switch (63) operates at a minimum duty cycle and increases towards a maximum duty cycle to prevent transformer (16) saturation and potential failure of the switch (63). In addition, the duty cycle detector circuit (61) alters the frequency at which the switch (63) turns on and off to reduce the power consumption of the power converter circuit (23).
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