How do turn signals work?
(→Power feed and flash unit) |
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From the flasher, a wire is run to the center wiper (or moveable contact) of the turn signal switch inside the steering column. | From the flasher, a wire is run to the center wiper (or moveable contact) of the turn signal switch inside the steering column. | ||
− | The flasher operates from internal heat on a tungsten bi-metallic "strip" that makes or breaks the contact at the switch side (or "power output" side) of the contact. | + | The flasher operates from internal heat on a tungsten bi-metallic "strip" that makes or breaks the contact at the switch side (or "power output" side) of the contact. The bi-metallic strip functions as it does by two dissimilar metals (Bi-metallic) with dissimilar expansion rates causing it to bend. |
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As the system lamp load is imposed on the flasher unit, the bimetallic strip heats up, and curls upwards, breaking contact to the switch. It then cools down very rapidly, and makes contact again, and the lamp load again heats the strip and it opens up. Thus: flash. | As the system lamp load is imposed on the flasher unit, the bimetallic strip heats up, and curls upwards, breaking contact to the switch. It then cools down very rapidly, and makes contact again, and the lamp load again heats the strip and it opens up. Thus: flash. | ||