ELECTRICAL AND ELECTRONIC SWITCHES AND CONTROLLERS, PROXIMITY LIMIT SWITCHES, ELECTRONIC SWITCHING AMPLIFIERS, TIME DELAY RELAYS, AMPLIFIER RELAYS, RPM MONITORS, LEVEL MONITORS, PLUG-IN ELECTRONIC SWITCHING AND AMPLIFIER MODULES, INDUCTIVE TERMINAL CONNECTORS, ELECTRONIC INTERFACE MODULES FOR ELECTRICAL INSULATION OF TWO OR MORE POTENTIAL VOLTAGE LEVELS AND HOUSINGS FOR ELECTRICAL AND ELECTRONIC DEVICES