Abstract: A method for the low-transient power control of electrical loads, particularly temperature-dependent loads electrically divided into essentially equal sub-loads connectable to an a.c. mains in order to receive power. Power control at low power levels utilizes alternately power-off phases, in which none of the sub-loads receive power for at least three a.c. half-waves, and heating phases, in which a temporal concatenation of at least a first and a second basic cycle of three a.c. half-waves supply power to each one of the sub-loads. The first sub-load receives power during one half-wave of the first basic cycle and the second sub-load receives power during one half-wave of the second basic cycle. The power is turned off during the other two half-waves of the first and the second basic cycle. Also disclosed is an electrical heating apparatus which embodies this method.

Abstract: A cooking apparatus comprises a glass-ceramic plate, at least one heat radiator arranged underneath the plate, at least one sensor arranged underneath the plate in an area which is shielded from the heat radiation, for measuring the temperature in this area, and a device for controlling the heating power in dependence upon signals supplied by the sensor. A simple and reliable method of measuring the temperature of the bottom of the cooking vessel can be obtained when, in the cooking apparatus the heat radiator is a halogen lamp system and the hotplate is a ceramic plate which is highly transparent to halogen-lamp radiation and has a degree of absorption of approximately .ltoreq.40%, the sensor engages against the underside of the ceramic plate, and the control device comprises an element for selecting a nominal.

Abstract: A method of achieving a comfortable temperature in the surroundings of a person, who is present in a room of low temperature, by means of a radiator is quickly reached and continuously maintained by continuously measuring the temperature in the surroundings of the radiator (18). While a direct thermal influence of the radiator is avoided, or the measurement is avoided, a required irradiation for the person is calculated from the temperature data by an electronic unit. The distance between the person and the radiator is measured, and the required power is provided to the radiator (18) in accordance with the calculated irradiation and the measured distance.

Abstract: The invention provides a method of controlling the boiling power for a water-containing vessel (10) which can be heated by a cook-top (11), for example a light cook-top, the amount of water evaporating at atmospheric pressure being sufficient to maintain an air-steam interface such that any residual air is expelled from the vessel (10) by an automatically controlled supply of heating power (12).

Abstract: In accordance with the invention an arrangement for controlling the heating power for a vessel (10) which can be heated by a cook-top (11), for example a light cook-top, by means of a sensor-controlled electronic device (19) can perform more functions in thatat least one (cooking-substance) sensor (18) is associated with the vessel (10) to detect the temperature of the foodstuffs (17, 15),the vessel (10) only communicates with the ambient air via a measurement tube (13) in which a (steam) sensor (20) and, optionally, a steam sensor (21) are arranged to detect the steam point of a liquid (14) present in the vessel, andall the sensors (18, 20, 21) are connected to the electronic device (19) and can be combined with one another via the electronic device.

Abstract: A power control circuit for at least two ohmic loads includes power semiconductors, switching elements and a control unit for adjusting the power consumption of the loads. In order to comply with international standards to avoid disturbances in mains supply systems when higher loads are switched, a simple and cheap circuit is described which is also suitable for smaller domestic appliances such as light cookers, flat-irons, cooking vessels etc. A control unit controls a switchable power semiconductor unit which can pass current in two directions and connects one or both loads to the single power semiconductor unit via the switching elements in a variety of circuit configurations so as to adjust the power to the loads as required.

Abstract: The invention proposes a method of controlling the boiling power for a water-containing vessel (10) which can be heated by a cook-top (11), for example a light cook-top, the amount of water evaporating at atmospheric pressure being exactly such that any residual air is expelled from the vessel (10) by an automatically controlled supply of heating power (12).

Abstract: A method of controlling the supply of power to electrical loads with a minimum of switching surges in which the loads are each electrically subdivided into at least two equal subloads. The subloads of each load can be connected each time arbitrarily in at least three main power stages to an A.C. mains. In order to obtain a minimum switching surge effect on the A.C. mains while providing finer power control six additional intermediate power stages are provided, in which starting from one of the three main power stages, the subloads are switched in a continuously repeated cycle of six A.C. half waves in the first intermediate power stages during the third and sixth half waves in each cycle and in the second intermediate power stages additionally during the second and fifth half waves each time to the next lower main power stage, which in the case of a series arrangement is that in which the power consumption is switched off.

Abstract: In a gas discharge lamp having a discharge vessel containing an ionizable gas filling and consisting of a translucent material, which is surrounded at a certain distance by a translucent outer bulb, the discharge vessel has a thermally insulating translucent envelope of a microporous aerogel.

Abstract: A method of controlling several clocked loads controllable individually and independently of each other, more particularly heating loads of an electric oven, for minimizing the demand on an alternating current mains due to switching transients. More particularly, the loads are energized in sequence to prevent flickering when the loads are coupled to a common phase of the alternating current mains are switched on each time at the beginning of their clock period. The clock periods of the various loads are of equal length. All loads neither switched off nor switched to full power in a switching cycle are connected to the mains so as to be interlinked in time in a manner such that, when the preceding load is switched off, the next load is switched on. Such a switching cycle is started again each time at the beginning of a common clock period independently of the length of the switching cycle.

Abstract: Cooker automatically controlling the heating process when bringing a food material to the boil on an electric hotplate and preventing it from boiling over at the end of the heating process. At the beginning of the heating process the power supplied to an electric hotplate can be set to a constant value which can be selected. A microprocessor continuously determines the rise in the temperature of the base of the pan as a function of time. At a pan-base temperature above about 70.degree. C. the actual value of the rise in temperature is compared with a present desired value and when deviations occur the heating power is switched over so as to approximate the actual value of the rise in temperature to the desired value. At a pan-base temperature above about 90.degree. C. a bending point in the temperature rise of the pan base is reached after which the heating power is switched off.

Abstract: A method of operating a high-pressure metal vapor discharge lamp at a periodic operating voltage of more than 500 Hz wherein the operating voltage is suddenly varied in phase at intervals, and preferably also wobbled in frequency, in order to avoid acoustic resonances in the lamp.

Abstract: A solar collector comprising a heat exchanger having a corrugated surface and an entrance window composed of evacuated transparent tubes respectively in contact with the corrugations.

Abstract: A solar collector comprising an elongate solid cylindrical body extending lengthwise into an elongate cylindrical Dewar-type vessel in a manner to form annular-shaped supply and outlet ducts for a heat-transport medium, the sum of the cross-sectional areas of the supply and outlet ducts being less than one-quarter of the inner cross-sectional area of the vessel.

Abstract: A solar collector comprising a U-shaped absorber sealed in an evacuated cover tube provided with a semi-cylindrical reflector on its inner surface, the U-shaped absorber being arranged between the cover tube axis and the reflector, with the central plane of the U-shaped absorber including the center lines of its legs and coinciding with the symmetry plane of the reflector.