| 摘要 |
<p>1,070,854. Road traffic signals on vehicles; lamp failure alarms. TUNG-SOL INDUSTRIES Inc. Aug. 25, 1964 [Aug. 27, 1963], No. 34757/64. Headings G4N and G4Q. A flasher circuit for vehicle signal lamps comprises a flasher unit in series with a reed relay, the lamps being connected in the energizing circuit of the relay so that if one of them is defective the relay will not operate and the lamps will not flash. In Fig. 2, a snapswitch 2 has a movable member which connects to contact 10 if an expansible wire 14 is cold and to a contact 8 if the wire is heated by a surrounding heater 20. When a switch S is closed a circuit is completed through contact 10 and the relay coil 34 to the signal lamps 46 and pilot lamp 48. The reed relay is adjusted so that it will not operate unless all the lamps light, in which case its contacts 36 and 38 close and energize the heater 20 to cause flashing; consequently the pilot lamp 48 will flash if the signal lamps are working and will glow steadily if one of the lamps has failed. In a modification' Fig. 3 (not shown), terminal 8 is connected to terminal 28 and a further lamp load is connected between terminal 28 and earth so that the two lamp loads flash alternately as the switch 2 makes connection to contacts 10 and 8. In a further modification. Fig. 5, the circuit includes a second relay 56 with normally closed contacts 70. When switch S is closed the lamps 46 light and energize relay 30 the contacts of which close and energize the heater 20; the pilot lamp 48 does not light because it is in series with heater 20. When the thermal switch changes over to contact 8 the relay 56 is energized and breaks the circuit to signal lamps 46, and the current through the relay is sufficient to light the pilot lamp 48.</p> |
