GF54.30-P-2010RT Setting Pushbutton Unit Illumination, Function

GF54.30-P-2010RT Setting Pushbutton Unit Illumination, Function

Component Identification:

Function requirements:
The switch and controls illumination is activated by the following components:
^ Switch on the vehicle lighting (as long as the standing lamp is active);
^ with automatic driving lights via the rain/light sensor.

When the standing lamp is switched on the position of the instrument and controls illumination button, dim (A1s5) of instrument and controls illumination button, bright (A1s4) is used as a controlled variable by the overhead control panel control unit. The rain/light sensor is not taken into account.
When automatic driving lights are on, the brightness of the switch and controls illumination is determined via the rain/light sensor. Its signals are evaluated by the overhead control panel control unit and thus the brightness is regulated via the control unit.







Terminal 58d on/off ratio
The lamps of the switch and controls illumination are actuated by means of a square-wave voltage U 58d (see top illustration):
^ The lamps are energized in the time t1, this is then followed by a break. The lamps are energized again after the break and so on.
^ The change occurs so quickly as to remain imperceptible to the human eye.
^ The ratio of times t 1 to T is called the duty cycle. where T is the constant cycle duration and t1 is the time during which power flows during a cycle.
^ The greater the duty cycle (that is to say the power flow duration t 1)), the greater the average power and therefore the brighter the lamps.


The voltage curve U 58d is sketched in the illustration as it is applied to the outputs "Circuit 58d" of the various control units. The upper sketch shows a duty cycle of 80 %, the lower a duty cycle of 40 %.
A duty cycle of 100 % corresponds to normal direct voltage. Power is not supplied when the duty cycle is 0 %.

Advantages of this type of illumination adjustment:
^ Considerably more efficient,
^ The brightness of the lamps remains independent of the number of lamps.
^ Each control unit, which is connected to the interior CAN or engine compartment CAN, can actuate lamps with the brightness specified by the instrument cluster.

When the standing lamp is OFF, the instrument cluster sends the message "circuit 58d duty cycle = 0 %".
When the standing lamp is "ON" the transmitted duty cycle can be adjusted with the instrument and controls illumination button, dim or instrument and controls illumination button, bright from 12 % to 100 %.