发明名称 |
Amplitude stabilized oscillator circuit |
摘要 |
An oscillator circuit is provided for stabilizing the amplitude of a HF oscillation of an audio signal. In such an oscillator circuit, an audio signal having a frequency in the range of 20 Hz . . . 20 kHz is coupled into the oscillator circuit, is modulated with a high frequency and is emitted in the form of an RF audio signal having a frequency of more than 2 MHz. Such an oscillator circuit is used for instance in an infrared transmitting unit, wherein a low frequency audio signal is transformed into a higher frequency infrared signal. The higher frequency audio signals are transmitted via infrared channel to an appropriate receiving unit-for instance to infrared head phones-which comprises a receiving unit having an appropriate demodulator and preferably also a stereo-decoder in order to reproduce the low frequency audio signals. The oscillator for stabilizing the amplitude of a high frequency oscillation comprises a resonant circuit which is coupled with a first transistor having a base terminal, an emitter contact, and a collector contact. The first transistor develops an output voltage at the emitter contact which is fed back into a base circuit of the first transistor. The collector contact of the first transistor is coupled to a supply voltage source. The supply voltage source is coupled to the base terminal of the first transistor via a resistor. The emitter contact of the first transistor is coupled with the base terminal of a second transistor. The second transistor has a collector contact which is connected to the base terminal of the first transistor for controlling the voltage at the base terminal of the first transistor.
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申请公布号 |
US5801592(A) |
申请公布日期 |
1998.09.01 |
申请号 |
US19970858611 |
申请日期 |
1997.05.21 |
申请人 |
SENNHEISER ELECTRONIC GMBH & CO. KG |
发明人 |
MANN, WOLFGANG;SCHAEFER, HORST |
分类号 |
H03C3/22;(IPC1-7):H03B5/12;H03L5/00 |
主分类号 |
H03C3/22 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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