the lighting module 3 may be an led module for instance for enabling the electric lamp 1 to retrofit a conventional fluorescent lamp like a tl lamp said led module 3 may comprise an inorganic led a plurality of leds an oled or another type of solid state light source the lighting module can also be embodied as an incandescent lamp a fluorescent lamp an hid lamp or any other type in this embodiment the lighting module 3 is powered by a voltage applied between the two terminals similarly to a conventional tube lamp in steady state operation to this end an automatic switch 6 is arranged between each terminal 4 and an associated pair of connection pins 5 each automatic switch 6 is controlled by an operatively connected voltage sensor 7 which is in turn on its input side electrically connected between the pins 5 in its associated pair of pins whereby it measures the respective voltages v a v b across these connection pins 5 when the left sensor 7 a determines that the left voltage v a has risen above zero or above a predefined threshold the left automatic switch 6 a closes the connection between the left terminal 4 a and one of the left pins 5 aa the left switch 6 a reopens the connection when the left voltage v a goes down to.