Abstract:
A buck converter for operating at least one LED. In this case, the buck inductor comprises a first buck inductor and a second buck inductor, wherein a charge pump is coupled between the coupling point of the two buck inductors and a supply connection of a control apparatus which is used for actuating a buck switch.
Abstract:
A Buck converter may include an input for connecting a DC voltage source; an output for connecting an LED; and a diode, an inductor and a main switch; wherein the diode and the main switch are coupled in series, wherein the inductor is coupled between the connecting point for the diode and the main switch, and a first output connection, wherein the converter further includes: a first auxiliary switch supplied with a first voltage; and a second auxiliary switch supplied with a second voltage, wherein the first auxiliary switch and the second auxiliary switch are coupled to the main switch such that the first voltage stipulates the switch-off time for the main switch and the second voltage stipulates the switch-on time for the main switch.
Abstract:
A buck converter for providing a current for an LED includes an input for connection of a DC voltage source; an output for connection of the LED; and a Buck diode, a Buck inductor and a Buck main switch which has a control electrode, a working electrode and a reference electrode. The diode and the main switch are coupled in series, wherein the connecting point between the diode and the main switch is coupled to the second output connection. The converter includes: an auxiliary winding which is coupled to the inductor and has a connection which is coupled to the second input connection and a connection which is coupled to the control electrode of the switch, wherein the auxiliary winding is coupled to the inductor such that, when current is flowing through the switch, a current is provided through the auxiliary winding to the control electrode of the switch.
Abstract:
A Buck converter may include an input for connecting a DC voltage source; an output for connecting an LED; and a diode, an inductor and a main switch; wherein the diode and the main switch are coupled in series, wherein the inductor is coupled between the connecting point for the diode and the main switch, and a first output connection, wherein the converter further includes: a first auxiliary switch supplied with a first voltage; and a second auxiliary switch supplied with a second voltage, wherein the first auxiliary switch and the second auxiliary switch are coupled to the main switch such that the first voltage stipulates the switch-off time for the main switch and the second voltage stipulates the switch-on time for the main switch.
Abstract:
A circuit arrangement is provided, which may include an input; an output; an inverter, configured to provide an AC supply voltage from a DC supply voltage; a control device configured to drive the inverter, the control device being configured to initiate a preheating phase once a preheating criterion has been met; a resonant circuit having a resonant inductor and having a resonant capacitor; and a transformer configured to preheat electrodes of a gas discharge lamp; wherein the primary winding of the transformer is connected in series with the resonant capacitor and is connected directly to the reference potential of the control device, and an electrical switch is coupled in parallel with the primary winding of the transformer, which switch has a control connection, which is coupled to the control device being configured to transfer the electrical switch into its electrically conducting switching state once the starting criterion has been met.
Abstract:
The present invention relates to an electronic ballast for discharge lamps, for example low-pressure discharge lamps, having a converter having a switching element and a two-part lamp inductor which is connected upstream and downstream of the discharge lamp. An electronic ballast according to the invention has a smoothing circuit which reduces voltage jumps caused by switching operations in the converter at the lamp terminals.
Abstract:
The present invention relates to an electronic ballast for discharge lamps, for example low-pressure discharge lamps, having a converter having a switching element and a two-part lamp inductor which is connected upstream and downstream of the discharge lamp. An electronic ballast according to the invention has a smoothing circuit which reduces voltage jumps caused by switching operations in the converter at the lamp terminals.
Abstract:
The radiation power emitted from the UV radiation sources (2) in a weathering apparatus is controlled such that the radiation power of each of the radiation sources (2) is measured in a predetermined spectral range of the radiation emitted from the radiation sources, with the spectral range being chosen such that the measured radiation power is representative of the radiation power in the UV, an averaged radiation power is calculated from the measured radiation powers, and the averaged radiation power is used for controlling the electrical power to be supplied to the radiation sources (2). In particular, the control process can be carried out in such a way that the same electrical power, within a predetermined tolerance bandwidth, is supplied to each of the radiation sources (2), and the averaged radiation power is kept constant over time at a desired nominal value.
Abstract:
In the case of circuit arrangements for operating discharge lamps (Lp1, Lp2) which include a charge pump for reducing line current harmonics, an energy imbalance occurs when the lamps are started. In order for this not to lead to components being destroyed, but for sufficient ignition voltage nevertheless to be generated at the lamps (Lp1, Lp2), a threshold switch (MOV, TH) monitors the frequency of an inverter included in the circuit arrangement.