发明授权
- 专利标题: High voltage message waiting circuit
- 专利标题(中): 高电压消息等待电路
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申请号: US832485申请日: 1997-04-02
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公开(公告)号: US5768366A公开(公告)日: 1998-06-16
- 发明人: Mario E. Jauregui , Spencer L. Hermanson , Ronald S. Lesniak , Elaine C. He
- 申请人: Mario E. Jauregui , Spencer L. Hermanson , Ronald S. Lesniak , Elaine C. He
- 申请人地址: CA San Jose
- 专利权人: Teledex Corporation
- 当前专利权人: Teledex Corporation
- 当前专利权人地址: CA San Jose
- 主分类号: H04M1/82
- IPC分类号: H04M1/82 ; H04M3/537 ; H04M9/02 ; H04M9/00
摘要:
A message waiting circuit comprised of a pair of electrical leads which carry a message waiting signal, a capacitor for storing electrical energy extracted from the message waiting signal, a transistor for allowing the capacitor to charge when the message waiting signal is within a predetermined range; a Darlington transistor for causing the capacitor to discharge; and a light emitting diode (LED) which emits light when the capacitor discharges. The flashing LED indicates that a message is waiting for a user of the telephone set associated with the message waiting circuit. Approximately ten to twenty-five message waiting circuits and associated telephone sets can be connected to a single telephone line.
公开/授权文献
- USD342949S Speaker box 公开/授权日:1994-01-04
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