Abstract: The invention relates to a dental furnace with a heating chamber, with at least two heating elements acting on the heating chamber and one control apparatus, which interacts with the heating elements, for the voltage supply to the heating elements. The control apparatus (22) supplies at least two heating elements (12) separately with voltage. In addition, the control apparatus (22) matches the power output of at least one heating element (12) to the requirements of the temperature distribution in the heating chamber (30).

Abstract: The watching apparatus is provided with a radar probe, and is made such as to detect the presence of human beings. The radar probe includes a command unit and a branching element, inserted between an oscillator circuit and a transmitter stage, as well as a superposing circuit (5), in which a signal, derived from the radar transmitter, is superposed with an echo signal received by a receiver stage. The radar probe is made such as to work as an interference radar, and a delay circuit is inserted into the transmitter-receiver path between the branching element and the superposing circuit in order to increase the travelling time of the radar signal with respect to the branched off signal.

Abstract: An electronic control device for the contactless control of a unit, e.g., a plumbing unit, especially a urinal, with at least one transmitter for sending directed light signals, and with a receiving device. The receiving device receives signals reflected from a scanned object and sends them to a circuit acting on the unit. The transmitter and the receiving device form an optical triangulation arrangement, wherein reflections are received from the background and from a predetermined detection zone to mask the said background.

Abstract: To guarantee a higher reliability of operation, the capacity of a battery to reliably open and close a water valve and to operate a microprocessor is continuously checked. To do so, a plurality of reference voltages are formed. The current voltage of the battery is compared with these reference voltages, and the state of the battery is indicated on the basis of this comparison with, e.g., an LED.

Abstract: The device has an optical scanning head (3) with a radiation source (17), as well as with a sensor (21). The scanning head (3) transmits a signal toward a background (9, 14), e.g., a washbasin, and receives signals diffusely reflected from that background. The signals (11) received are sent to an electronic control unit (22) for controlling, e.g., a valve (3). The device is arranged, e.g., in the water outlet (2) of a washstand appliance.