Circuit for fluorescent signaling device

摘要

In conventional fluorescent signaling devices the filament is fed with 50 Hz alternating current and the multiplex frequency of the signal ranges similarly in the area of 50 Hz, so that brightness variations occur with the difference in frequencies. A simple means for avoiding disturbing effect is the circuit of the present invention which divides the heating alternating current voltage into several stages and connects the negative terminal of the supply voltage of the fluorescent signaling device to one of the intermediate stages of the heating alternating current voltage depending on the signaling point that at the instant concerned happens to be lighted.