40/49MHz monitoring system implemented by using phase-locked loop technology

A monitoring system, phase-locked loop technology, applied in the direction of automatic power control, electrical components, etc., can solve the problems of complex production and debugging, increase production cost, complexity of mid-cycle tuning, and high defect rate, and achieve material cost reduction and integration. The effect of simple machine assembly and improved production efficiency
CN102332913AInactive Publication Date: 2012-01-25MC DEVICES CO LTD
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Patent Information

Authority / Receiving Office
CN Β· China
Patent Type
Applications(China)
Current Assignee / Owner
MC DEVICES CO LTD
Publication Date
2012-01-25
Estimated Expiration
Not applicable Β· inactive patent

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Abstract

The invention relates to a 40 / 49MHz monitoring system implemented by using a phase-locked loop technology. A scheme which adopts a transmission chip integrated with a phase-locked loop, a read-only memory and an RF (radio frequency) power amplifier to replace the conventional crystal frequency multiplication to carry out transmission not only dispenses with an intermediate frequency transformer used by the crystal scheme to filter the multi-harmonic and the fundamental harmonic, thus solving the problems of production complexity and high defect rate caused by the tuning and debugging of the intermediate frequency transformer, but also simplifies the system scheme under the condition of keeping the low-cost advantage of the crystal frequency multiplication scheme. The 40 / 49MHz monitoring system also adopts a receiving chip integrated with a phase-locked loop, a read-only memory, a radio frequency amplifier, a mixer, a demodulator and an audio power amplifier, consequently, the integration degree and stability of the system are greatly increased, multi-frequency selection can be easily carried out, the usage of a polycrystal is not needed, the standard frequency point specified by all industries is fixed by the integrated read-only memory, and does not need to controlled and locked by an MCU (microprogrammed control unit), and thereby the device cost is saved.
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Description

technical field

[0001] The invention relates to a 40 / 49MHz monitoring system realized by using the phase-locked loop technology as the core technology. Background technique

[0002] Monitors are consumer electronics products that have been gradually popularized and applied in the European and American markets in the past 20 to 30 years. They are mainly used for daily monitoring of babies, the elderly, and patients in homes, nursing homes, nursing homes, and hospitals. With the rapid development of the economy, the rapid upgrading of electronic products, and the fierce competition among industry companies, product cost control has become an important threshold for consumer electronics. Compared with 2.4G digital monitors, the 40 / 49M monitoring system has a huge cost advantage so that it always occupies a large proportion of the monitor market. The traditional 40 / 49MHz monitoring system basically uses more than a dozen MHz crystal oscillations to obtain the working frequency ...

Claims

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