A first switching arrangement connects power return lines selectively to an electrical ground, a voltage supply or an electrically isolated terminal, independent of the other power return lines.

The electrical return of the probe is a lid speculum (202) which maintains the eyelids in an open position.

The steel rails of the tracks act as the electrical return.

The method reduces maximum currents carried by the power supply lines and power return lines by temporally spreading current pulses for powering the heater zones.

Magnet arrangements of said variety are, preferably, used for electric re-positioning in liquid valves.

This process makes it possible to easily identify the anatomical positional relation of an abnormal electric turning path if occurring in the cardiac muscle.

The electrical feedback signals from the process valve are also routed to the control cubicle.

Subareas (451A, 451B) are provided on the piezo-ceramic layer (450) to produce an electrical feedback signal when the actuator is piezo-electrically deflected.