Device for producing light

摘要

In order to increase the light yield or to save energy while maintaining the same light yield, it is known to supply the incandescent filaments of two electrical lamps with pulse sequences of different polarity, which are shifted by half a cycle with respect to one another. The increased complexity resulting from the installation of two lamps is, however, not economically viable in comparison with the advantages. A considerably greater energy saving or light yield is, however, produced if both incandescent bodies (3, 4) are arranged parallel in a common glass bulb (1) and they are arranged at a very short distance from one another. This results in the heat radiation from that incandescent body through which current is flowing in each case heating up the other incandescent body through which current has just flowed. This leads to less cooling of each incandescent body during the period when current is not being passed through it and thus to higher efficiency, since the increased temperature of the incandescent bodies results in a greater luminous flux without it being necessary to increase the electrical power. The glass bulb (1) expediently has an infrared coating which reflects the heat radiation from the incandescent bodies (3, 4) onto them. <IMAGE>