Title:
EXCESS CURRENT PROTECTING POWER SWITCH
Document Type and Number:
Japanese Patent JPS6439223
Kind Code:
A
Abstract:
PURPOSE: To form a simple circuit at a low cost, by using a photo-coupler for an excess current detecting element, and a thyristor for a breaking element.
CONSTITUTION: When a line voltage is turned into voltage determined by a Zener diode ZD1 and a transistor Tr 1, or more voltage, then the transistor Tr 1 and a thyristor SCR 1 are turned ON, and a transistor Tr 2 is turned ON, and the Tr 1 is turned OFF. In this state, current is fed to a load. When constant or more current flows to the load, then a photo-coupler 14 is turned ON, and a thyristor SCR 2 is triggered. Then, the thyristor SCR 1 is turned OFF, and feed is interrupted.
Inventors:
MURASE MAKOTO
Application Number:
JP19499687A
Publication Date:
February 09, 1989
Filing Date:
August 04, 1987
Export Citation:
Assignee:
NEC CORP
International Classes:
H02H3/10; H03K17/08; H03K17/73; H03K17/78; (IPC1-7): H02H3/10; H03K17/08; H03K17/73; H03K17/78
Attorney, Agent or Firm:
Yutaro Kumagai