Abstract: The present invention provides an electronic circuit with adjustable delay time for turning on or off an application device or an electronic load. The electronic circuit according to the present invention comprises a switch element for controlling power supplied to a load; and an activation element, coupled to the switch element, for activating the switch element to control power supplied to the load. The activation element includes a sensor for sensing whether there is a change in condition and for delaying activation by the activation element of the switch element upon sensing a change in condition. In one embodiment of the invention, the sensor includes a positive temperature coefficient (PTC) element; the switch element includes a metal-oxide-semiconductor field effect transistor (MOSFET); and the activation element further includes a capacitor and a switch. A change in condition includes an overload and an increase in the ambient temperature.

Abstract: A method of making varistor chips is disclosed. A workpiece of varistor material is sliced into slices of varistor material. The slices are in turn diced to make the varistor chips. The chips are etched in an etchant such as dilute citric acid to remove from their surfaces varistor material damaged during the slicing and/or dicing operations. Otherwise, the damaged varistor material adversely affects the leakage current characteristics of the varistor chips.