专利名称：RESIDUAL CURRENT DEVICE
发明人：Patrick Ward
申请号：US12312508
申请日：20080111
公开号：US20100046127A1
公开日：
20100225
专利内容由知识产权出版社提供
专利附图：
摘要：A residual current device compris a circuit (CT, ) for detecting a current
imbalance in an AC supply to a load indicative of a residual current and providing a corresponding output. A relay RLA has contacts SW in the AC supply to the load. The relay contacts SW automatically clo when a closing current is pasd through the relay
and is thereafter maintained clod so long as a holding current, less than the closing current, pass through the relay. A capacitor C is connected to the AC supply in parallel with the relay RLA such that, upon application of power from the AC supply, current flows to the charge storage device. An electronic switch SCR in ries with the relay is turned on when the voltage on the capacitor exceeds the breakover voltage of a Zener diode ZD to allow discharge of the capacitor through the relay to provide a current exceeding the closing current, the AC supply thereafter providing a holding current for the relay at least when the supply is at a certain minimum voltage. An output from the current imbalance detecting circuit opens contacts SW in ries with the relay to interrupt the current flow through the relay.
申请人：Patrick Ward
地址：Co. Galway IE
国籍：IE
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