Direction indicating flasher device for vehicles with filament failure indication

A flasher device for use in a vehicle comprising:

• at least two groups of indicator lamps including filaments;
• a flasher starting switch for selecting a selected group of said at least two groups of indicator lamps, said flasher starting switch having a plurality of stationary contacts and connected to said groups of indicator lamps;
• supplying means for supplying an intermittent current alternating between first and second states to a selected said group of indicator lamps to flash said selected group of lamps, said supplying means, said flasher starting switch and said selected group of indicator lamps forming a complete current path;
• time width measuring means for measuring the time width of changing pulses of said intermittent current caused by the time constant established by the changes in resistance of said filaments after said intermittent current is changed to a different said state;
• detecting means connected to said time width measuring means for detecting breakdown of one of said filaments when said time width is changed and for outputting a break down signal;
• control means connected to said detecting means for controlling said supplying means to vary the frequency of generation of said intermittent voltage in response to said breakdown signal.

A flasher device for use in signalling vehicle direction comprising:

• a group of direction indicating lamps;
• drive means for selectively supplying an intermittent voltage at a selected frequency to said group of lamps to cause them to flash;
• voltage sensor means, operatively connected to said group of lamps, for sensing a resistance related voltage across said group of lamps;
• control means, responsive to said voltage sensor means and operatively connected to said drive means for detecting a change in said resistance related voltage to thereby detect a failure of one or more lamps, said control means controlling said drive means to vary the frequency at which said intermittent voltage is supplied to said group of lamps to indicate failure of at least one of said group of lamps;
• said voltage sensor means sensing said resistance related voltage without substantial insertion of impedance in series with said group of lamps, thereby preventing significant reduction of voltage or power supplied said group of lamps.