An electronic ballast for a lamp has at least one dimming value control input and a control unit configured to set the dimming value of the lamp, wherein arranged downstream of the dimming value control input are: a signal output state detecting unit configured to acquire at least one of a signal output state in which the signal level of a signal fed to the dimming value control input overshoots a predetermined limit value, and a signal output state in which it undershoots a predetermined limit value, and a measuring unit configured to measure the duration of a signal output state, the control unit configured to set a dimming value of the lamp being configured to set the dimming value on the basis of the measured duration of the signal output state.