发明授权
- 专利标题: Step-down constant-current transformer
- 专利标题(中): 降压型恒流变压器
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申请号: US09786904申请日: 2001-06-18
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公开(公告)号: US06541947B1公开(公告)日: 2003-04-01
- 发明人: Bernd Dittmer , Roman Gronbach
- 申请人: Bernd Dittmer , Roman Gronbach
- 优先权: DE19841341 19980910
- 主分类号: G05F140
- IPC分类号: G05F140
摘要:
A step-down constant-current transformer including a controllable switch downstream from the one input and connected in series to a choke, a capacitor connected in parallel at the output, and upstream from the choke, a second controllable switch in parallel. Both controlled switches are MOSFET transistors. A control unit, in particular a pulse-width control unit, is provided for the MOSFET transistors. The voltage across the parallel-connected MOSFET transistor is monitored to determine whether a reverse current, i.e., a current flowing through the choke from the output in the direction of the input of the constant-current transformer, or an electric potential at the center tap of the half-bridge formed by the two MOSFET transistors is detected. For this purpose, a comparator and an AND circuit are provided, which, in the event of such a reverse current, block the parallel-connected MOSFET transistor to prevent the reverse current.