8135 meter - brightness?

[ben]

Is there any way to dim the display on the 8135? I installed two of them on my boat, one as a voltmeter and one as an ammeter, and now it's almost impossible to sleep in the main salon - they light everything up with their bright blue light.

I'm an electronics engineer and worked as a tech for a number of years, so I'm not afraid to pick up a soldering iron if necessary.

[Entropy]

One usually installs resistors in series with LEDs to control the supplied voltage which controls their brightness--usually to drop the voltage so one doesn't burn up the LED which are rather low voltage devices. There may be a resistor in series with the digital led display only on the PCB that you could remove with Chip Quick (it looks like it would be a SMD resistor and chip quick is the easiest way to remove SMD components by hand.) Chip Quick from Spark Fun. Resistors from Jameco, Mouser, Digikey, etc... There are gads of tutorials on SMD removal and soldering on line and You-Tube. I don't have a schematic or know if you do--so you might have to trace out the PCB.

Having said that--from looking at the web page for this thing: It will operate with a supply voltage anywhere from 6 - 15 volts. I would try dropping the voltage to the whole thing down close to 6 volts. You could use a DC-DC converter or power supply to do this or cheaper install a resistor in series to the thing. Chances are that would result in a drop in voltage to the LED display. A rough calculation off the top of my head results in a 47 ohm resistor to drop voltage from 12 to 6 volts assuming a 130 amp load per the specs on the product page and that you have this wired to a 12 volt supply- battery. You could get a 0-50 ohm pot and put that in series with one of the meters and experiment. That way you don't have to fool with the board and can tweak it.

Last idea is to put in dc rated latch-type switches of some sort so that you can just turn the meters off when you really aren't using them.