Page 320 - 05. Subyek Teknik Mesin - Automobile Mechanical and Electrical Systems Automotive Technology Vehicle Maintenance and Repair (Vehicle Maintenance Repr Nv2) by Tom Denton

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302 Automobile mechanical and electrical systems

Figure 3.96 Light cluster that uses LEDs

Figure 3.97 Stoplight and rear light twin fi lament bulb

examined later in this section. The bulbs are often combined with the rear lights
( Figs 3.96 and 3.97 ).
The operation of the fl asher unit is usually based around an integrated circuit.
The electronic type shown in Fig. 3.98 can operate at least four 21 W bulbs (front
and rear) and two 5 W side repeaters when operating in hazard mode. This will
continue for several hours if required. Flasher units are rated by the number of
bulbs they are capable of operating. When towing a trailer the unit must be able
to operate at a higher wattage. Most units use a relay for the actual switching as
this provides an audible signal. Thermal-type fl asher units are still used on older
vehicles. LEDs are now also being used in place of indicator bulbs. An indicator
warning appears on the dash ( Fig. 3.99 ).