发明名称 |
Leistungsquellenumschaltschaltung für ein tragbares Telefon |
摘要 |
<p>A switching circuit (30) in a portable telephone connects a gate of a field-effect transistor (Q1) to a voltage below the transistor's gate threshold voltage when the voltage at a first power source terminal (B) falls below a threshold voltage, thus disconnecting the first power source terminal (B) from a portable telephone power input terminal (B+) and connecting a second power source terminal (A) to the power input terminal (B+). The threshold voltage is set at a voltage above the minimum supply voltage of the portable telephone. The first power source terminal may be connected to a main battery and the second power source terminal may be connected to an adapter such as a battery eliminator adapter, hands-free adapter, or mobile transceiver adapter. This switching circuit prevents a call in progress from being disconnected when power sources are exchanged during a GSM burst.</p> |
申请公布号 |
DE19709806(B4) |
申请公布日期 |
2005.04.21 |
申请号 |
DE1997109806 |
申请日期 |
1997.03.10 |
申请人 |
MOTOROLA, INC. |
发明人 |
BARKAT, SHAKIL H.;BLACK, GREGORY R. |
分类号 |
H02J9/06;H03K17/30;H04B1/44;H04M1/00;H04M1/02;(IPC1-7):H03K17/06;H04M19/00 |
主分类号 |
H02J9/06 |
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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