发明名称 |
Start winding switch protection circuit |
摘要 |
A single phase, capacitor start electric motor is shown in which energization of the auxiliary winding is controlled by a triac. The triac is protected from excessive voltages caused by the vector sum of capacitor, line and induced voltages which can occur at turn-off of the triac. The triac is protected in several embodiments by a gated semiconductor switch serially connected to a current limiting or discharge resistor, both being coupled across the triac. The semiconductor switch has a voltage breakdown device connected in its gate circuit. When voltage across the triac exceeds a selected level the gated semiconductor is turned on thereby drawing sufficient current momentarily to limit the voltage across the triac to a safe level and allowing the capacitor to discharge its voltage through the auxiliary winding circuit. In another embodiment a stack of high voltage bilateral triggering devices is placed across the triac.
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申请公布号 |
US5103154(A) |
申请公布日期 |
1992.04.07 |
申请号 |
US19900529034 |
申请日期 |
1990.05.25 |
申请人 |
TEXAS INSTRUMENTS INCORPORATED |
发明人 |
DROPPS, KEVIN J.;THOMPSON, HERBERT A. |
分类号 |
H02H9/04;H02P1/44;H03K17/0814 |
主分类号 |
H02H9/04 |
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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