1. A RELAY COMPRISING A SEALED REED SWITCH HAVING MAGNETIZABLE CONTACT-OPERATING BLADES, AN ELECTRIC COIL FOR ESTABLISHING WHEN EXCITED A MAGNETIC FIELD THROUGHOUT A CERTAIN PATH, SAID PATH INCLUDING A MAGNETIZABLE PART AND SAID BLADES, A MOVABLY MOUNTED CORE PIECE POSITIONED IN SAID PATH AND MOVABLE TO AND FROM SAID MAGNETIZABLE PART, RESILIENT MEANS BIASING SAID CORE PIECE TO ESTABLISH A COMPARATIVELY LARGE SPACE WITH RESPECT TO SAID PART IN SAID PATH WHEN THE COIL IS DEEXCITED, SAID CORE PIECE BEING MAGNETICALLY DRAWN TOWARD SAID PART AGAINST THE BIAS OF SAID BIASING MEANS TO REDUCE SAID SPACE UPON SUBSTANTIAL EXCITATION OF THE COIL, WHEREBY SAID MAGNETIC FIELD IS STRONGLY ENOUGH ESTABLISHED THROUGHOUT SAID PATH TO MAGNETIZE SAID BLADES FOR OPERATION THEREOF.