Switching device for projection lamp

Abstract

A switching device for a projection lamp of a projector wherein an electrical control device, which is separated from the projector and which supplies the projector lamp with electrical energy, is controllable from the projector by a control device via at least one control connection disposed on the projector. FIELD OF THE INVENTION The invention relates to a switching device for a projection lamp, especially a gaseous discharge lamp, which needs a relatively large electrical control unit that normally is separated from the projector. BACKGROUND OF THE INVENTION Such a device is known from U.S. Pat. No. 3,039,022. With this device it was disadvantageous that all control functions were carried out by means of the electrical control unit, so that the transmission of control commands from the electrical control unit to the mechanical parts of the projector had to be effected by means of relatively expensive magnets. SUMMARY OF THE INVENTION It is an object of the present invention to create a simplified and less expensive control means, which in accordance with another object of the invention is aided in its accomplishment in the manner that the control device is arranged on the projector in a manner known per se and the electrical control unit is controllable from the projector by means of the control device via at least one control terminal or connection provided on the projector. This offers the particular advantage that in a preferred embodiment the control circuit can be separated from the supply circuit of the electrical control unit, thus increasing the safety for the user and simplified safety instructions or regulations are able to be used for the projector itself, respectively.

Dependencies are inferred from the claim text.