In article ,
"Steve Lusardi" wrote:

Marc,
Please also note that the conventional solution of adding an adjustable
resister in series for dimming the light will not work with leds, as the
voltage to drive the led is quite specific and is different for each
available color. The correct way to dim leds is change the duty cycle with a
chopper, like a motor control for a PM motor.

In article ,
Bruce in Alaska wrote:

The "Age Old Solution" to your problem is to change the Lights to
RED colored Light Souces, which will illuminate the instruments,
but not effect your Night Vision. This is what happens when
Designers, design products for a Markket they havee no experience or
understanding of. Blue Light is the absolute Worst color for Night
Vision type operations.

Bruce in alaska

Steve and Bruce

the series resistor works of course. The LED's need 2 to 3.5 V
(depending on color etc), the difference to 12 V just heats the resistor
that is usually used as a good enough current source. The light is very
proportional to current flowing through the LED.

PWM is just an energy saving way of dimming. This is most likely what is
already provided.

I found the Compass to be illuminated by a conventional 3mm LED with
series resistors. I'll replace it with a red/orange one and appropriate
resistors.
To continue Bruce's thoughts: It will be best to use red LED's of around
610 nm wavelength (actually usually called orange), since the dark red
ones at 680 to 700 nm emit light that many people are very poor at
seeing. That is why aircraft and ship lights have to be of the 610 nm
wavelength.
(see http:
//www.periheliondesign.com/downloads/redandgreenledpositionlights.pdf)

Now I just have to find how to dissassemble the SmartCraft Speedometer
etc to replace the white lights (hopefully standard LED's) with red ones.
As for the remote control of the stereo, I'll probably just use a grey
filter to stick on.

Thank you for the ideas.

Marc

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