| 摘要 |
A wireless toy musical instrument, such as a guitar, includes a body member and electronic circuitry disposed within the body for transmitting the output of the musical instrument to a separate receiver such as a standard radio. The circuitry includes an audio section having a sound transducer which converts the audio signal generated by the strings of the guitar to a varying electrical signal comprising either solely a voltage or a combination of voltage and current. The circuitry also includes an oscillator section for generating a carrier signal operating at a predetermined radio frequency, the frequency being set by an LC circuit. The converted audio signal from the transducer is fed into the oscillator, the converted audio signal being combined with the carrier signal. Depending on the type of sound transducer used, a frequency modulation of the carrier signal is effected, either by the change of voltage, or current which is generated by the sound tranducer and applied to the carrier signal. In addition, depending upon the sound transducer used, the internal capacitance of the sound transducer changes also effecting a frequency modulation of the carrier signal. Further, the electrical signal from the sound transducer also effects an amplitude modulation of the carrier signal such that the subject instrument can transmit on either the AM band or FM band.
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