Abstract: A measuring technique, useful in diverse applications such as in joysticks and power tools, wherein an interfering member is positioned so that upon movement e.g. by a user a magnetic field, established by a solenoid coil, is altered and a change in a measured inductance of the coil is related to the position, or the extent of movement of the interfering member, relative to the coil.

Abstract: A water heater with a hot water compartment, the volume of which is decreased when hot water is discharged. The remaining hot water is prevented from mixing with replacement cold water. The volume of the compartment is increased again when cold water has been heated and is pushed into the hot water compartment. The water heater is divided into a receiving compartment for water at ambient temperature and a compartment from which heated water is discharged for normal usage. The previously heated water is thereby prevented from mixing with replacement cold water. All compartments can be heated or the compartments can be heated individually. The water heater keeps the hot water temperature high between usage activities, and is suited for an intermittent energy source, e.g. solar power.