Figure 2-55. - Lamp construction and configurations.
Small gas-filled incandescent lamps with tungsten filaments are used on automotive and construction equipment (fig. 2-55). The filaments supply the light when sufficient current is flowing through them. They are designed to operate on a low voltage current of 12 or 24 volts, depending upon the voltage of the electrical system used.
Lamps are rated as to size by the candlepower (luminous intensity) they produce. They range from small one-half-candlepower bulbs to large 50-candlepower bulbs. The greater the candlepower of the lamp, the more current it requires when lighted. Lamps are identified by a number on the base.
When you replace a lamp in a vehicle, be sure the new lamp is of the proper rating. The lamps within the vehicle will be of the single- or double-contact types with nibs to fit bayonet sockets, as shown in figure 2-56.Continue Reading