Patent ID: 7279848

Claim:
An electronic ballast for a lamp, comprising: a bridge circuit, which comprises at least one first switch (S 1 ) and a second switch (S 2 ), a center point (M) of the bridge circuit being defined between the first switch (S 1 ) and the second switch (S 2 ), said center point (M) being coupled on one side to a reference potential via the series circuit comprising a first capacitor (C 1 ) and a diode (D 2 ) and on the other side to a first connection ( 12 ) for the lamp (La) via an inductance (L 1 ); a control unit ( 10 ) for the purpose of driving the first switch (S 1 ) and the second switch (S 2 ), the control unit ( 10 ) having a supply connection (VCC) which is coupled to the connection point between the first capacitor (C 1 ) and the diode (D 2 ), the voltage across the supply connection (VCC) being limited in terms of its amplitude, and having a measurement signal input ( 16 ) for the purpose of feeding a measurement signal (U C13 ) to the control unit ( 10 ); and characterized in that: the measurement signal input ( 16 ) is coupled to the connection point between the first capacitor (C 1 ) and the diode (D 2 ); and the electronic ballast further comprises a signal delay unit (R 12 ) in order to delay the signal (U D2 ) at the connection point between the first capacitor (C 1 ) and the diode (D 2 ) before it is fed to the measurement signal input ( 16 ).