Abstract: The invention relates to a pump (10), having a pump head (12), which has a pump chamber (11), and having an electric motor (14), which drives the pump head (12) and has a stator (40) and a rotor (38), the rotor (38) being connected to the pump head (12) and being disposed in a rotor chamber (82) open toward the pump chamber (11).

Abstract: In an electronically commutated direct-current motor having a stator (14) with a multi-phase stator winding (15) and a housing (11) receiving the stator (14), having a commutation device (21), disposed in the housing (11) for consistent connection of the winding phases to a direct voltage from the electrical system, which has a plurality of semiconductor switches (22) and an electronic control unit (26), received by a printed circuit board (24), for triggering the semiconductor switches (22), and having a connection plug (13) for delivering the direct voltage from the electrical system, in order to provide a more-robust embodiment of the commutation device (21), all the electronic components of the commutation device (21) that carry power currents, such as the connection plug (13), semiconductor switches (22), electrolyte capacitor (25), and so forth, are contacted on a stamped grid (23), with which the electrical connection with the stator winding (15) and the printed circuit board (24) is established.

Abstract: An electronic circuit which has a voltage terminal, a switch, a voltage stabilizer and a computer. In addition, an interface terminal is provided, via which the computer can exchange data via an interface. After a supply voltage is applied at the voltage terminal, the switch (11) is initially closed so that the circuit has an extremely low quiescent current. A signal at the interface terminal causes the switch to close and the voltage stabilizer and the computer are activated.

Abstract: An electronically commutatable motor is described, the stator field windings of which can be connected to a commutation frequency having a DC supply voltage to generate a rotating field for the permanent magnet rotor and can be disconnected from it, the field windings being switchable via semiconductor output stages which can be activated via control signals with the commutation frequency of a control unit and whose operating conditions change as a function of a specified or specifiable setpoint. The disadvantages of motors with pulse-width-modulated control of the field windings can be avoided with simplified motor control in that the DC supply voltage is supplied to a DC transformer whose output voltage for the semiconductor output stages with the field windings changes as a function of the setpoint and that the control unit fully activates the semiconductor output stages continuously with unclocked control signals with the commutation frequency independently of the setpoint.

Abstract: A method of operating a resistance heating element and a device for carrying out the method are described. During a first step, the resistance of a resistor of the resistance heating element is determined at a known base temperature. In a second step, the resistance setpoint value is determined as a function of resistance of the resistor at the known base temperature and known temperature coefficients. The resistance heating element is activated by approximately setting the resistance setpoint value in order to heat the resistance heating element to the given setpoint temperature.

Abstract: The present invention provides a device for measuring air quality. The device includes at least one sensor with a sensor resistance which is converted via signal processing into an output signal, the gas sensing or air content sensing device having its sensor(s) with electrical resistance that is a function of the air quality, such sensors being connected in an astable flipflop circuit arrangement with a first feedback resistor, a second feedback resistor, a capacitor and a comparator--where the first resistor is coupled between the inverting input and output of the comparator, and the second resistor is coupled between the noninverted input and the output of the comparator, and the sensor(s) is/are coupled between a reference potential and the noninverting input of the comparator. The output signal has a period which is related to the sensor resistance.

Abstract: A circuit arrangement for air quality measuring having at least one sensor element which has resistors the resistance of which changes depending on the air composition. The circuit arrangement has an evaluation circuit for the sensor signals and includes a logarithmic circuit.

Abstract: A headlamp for motor vehicles has a reflector, a gas discharge lamp, a front plate covering a light exit opening of the headlamp, and a filter arranged in a beam path of light beams reflected by the reflector and light beams transmitted directly to the front plate and at least partially absorbing light in a UV wavelength region.

Abstract: A headlamp for a power vehicle comprises a reflector having an apex, a light source arranged in the apex of the reflector, and a dimming device which is formed so that in a position for high beam it allows light from the light source to reach a lower reflector region or allows the light to exit the same, and in a position for low beam it keeps away light from said light source from the lower reflector region or blocks light reflected from the lower reflector region. The light source is formed as a gas discharge lamp with an axial light arc, an upper reflector region is formed for producing a light distribution for low beam while the lower reflector region is formed for producing a light distribution for high beam.

Abstract: A headlight for motor vehicles has a reflector, a gas discharge lamp inserted in the reflector, an electrical pre-switching device arranged to supply the gas discharge lamp with high voltage, a lamp support via which the gas discharge lamp is inserted in the reflector, a detachable protective cap which covers the lamp support and the gas discharge lamp at their rear, an electrical line connected with the pre-switching device, and a switch arranged in the line and openable when the protective cap is removed so that the operation of the gas discharge lamp is prevented when the switch is opened.

Abstract: A headlamp for a power vehicle comprises a reflector having an apex, a light source arranged in the apex of the reflector, and a dimming device which is formed so that in a position for high beam it allows light from the light source to reach a lower reflector region or allows the light to exit the same, and in a position for low beam it keeps away light from said light source from the lower reflector region or blocks light reflected from the lower reflector region. The light source is formed as a gas discharge lamp with an axial light arc, an upper reflector region is formed for producing a light distribution for low beam while the lower reflector region is formed for producing a light distribution for high beam.