发明名称 |
Tone Burst Generator |
摘要 |
A tone burst generator where a continuous tone voltage is applied across two series-connected semiconductor switches each having an ON state and an OFF state. A first control circuit controls the state of the first switch and the variable impedance in an intermediate region between its ON and OFF states to cause gradual, well-defined OFF/ON and ON/OFF transitions of the first switch. As a result of these first switch transitions, a voltage tone burst is generated that has precisely defined edges to eliminate clicking noise. The continuous tone voltage is of only one polarity-it has a non-zero DC component and an AC component having a peak-to-peak variation less the twice the magnitude of the non-zero DC component. A second control circuit controls the state of the second switch and the variable impedance in an intermediate region between its ON and OFF states to cause well defined ON/OFF and OFF/ON transitions of the second switch.
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申请公布号 |
US5373552(A) |
申请公布日期 |
1994.12.13 |
申请号 |
US19930013454 |
申请日期 |
1993.02.04 |
申请人 |
AT&T CORP. |
发明人 |
FITE, WAYNE C.;PRANAITIS, JR., WILLIAM F. |
分类号 |
H04M15/00;(IPC1-7):H04N17/00;H04N15/00 |
主分类号 |
H04M15/00 |
代理机构 |
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