On 18/11/2016 00:24, Dave Plowman (News) wrote:
In article ,
Roger Hayter wrote:
Brian Gaff wrote:

This sounds like a simple circuit charging up a capacitor to bias on a
transistor. The problem probably is that the settings used assume a
lower resistance load than the led. It depends if its using someform
of feedback to achieve the more smooth gradual illumination.
Brian

Nowadays such things are more often done with a microprocessor. It is
probably actually cheaper than the high value stable capacitor you would
need tor the analogue timer. My bathroom fan does its timer this way,
making modifying its behaviour a work in progress.

Could well be. Have looked to see if there are any dedicated chips for
this job - but so far no luck.


Our car has this also, had a look at the circuit board and as expected
it's just a COB. The one in ours also has canbus as well as power, so
it's at least possible the dimming is done by the BCM.

I dare say that anyone familiar with a PIC could program one up to do
the job of a basic fade in/out in a few minutes.
Anyone on here want to offer?