Cobalt Alloy Wire for High-Current Reed Switches

摘要

Recent years have seen increases in electronically controlled system equipment and electric current capacity. Therefore the demand for switches capable of handling high current is rising. Mercury reed switches have been used for high-current switch until now. Since mercury is a substance of concern, mercury reed switches have been changed to reed switches in which mercury is not used. However, when a temperature rises largely as energization progresses by Joule heat effect, lead wires lose their ability to carry magnetic flux, and reed switches become less sensitive. Due to these problems, reed switches were not used for high-current switches. We have developed cobalt-nickel-iron alloy wire for high-current switches that demonstrate excellent characteristics similar to the conventional alloy lead wire. The new alloy wire suppresses heating due to energization and has high Curie temperature, i.e. less susceptibility to lose magnetic characteristics. The reed switch using the new alloy wire is expected to be applied to LEDs in automobile stop lamps.