Amendments by Wolfgang Steiner
The halogen lamp is especially stable with high light yield and unlike the electric light bulb it does not blacken the glass bulb during use. Their lifespan is not
necessarily higher than
that of an electric light bulb of the same size, which amounts to approx. 150 hours of operation.
How it works
A special gas-filling using iodine and bromine additions causes the wolfram (tungsten) particles of the glowing element to return to the element, thus not hindering the light emission from the bulb. The light bulb
becomes hotter and causes a higher luminance.Shown in the above figure 1 is a typical double-filament bulb (Bilux-lamp). The upper filament and reflector are for the dimmed headlights
which may only shine onto the upper part of the reflector. The lower filament is for the high beam, using the whole reflector.
H1 to H3 and H7 are single filament, H4 (above figure 1) to H6 are double-filament lamps. The H7 lamp is used in modern four-headlight systems with free form
Unfortunately, the lifespan is limited, due to the high pressure in the lamp it is very sensitive to fluctuating voltage. When changing the lamp caution must be applied because of the high pressure in the glass bulb.
The dual filament lamp H4 belongs more to the system with two headlights. It produces low beam or high beam with various coils. The lower reach of low beam is created by a sheet metal cover, that is beveled on
one side due to the asymmetry of this light. 07/08
|Usually, the input power is 55W.|
This can also be higher.