I have a prosport boost and oil pressure guage...and they are both WAY too bright. Especially on long drives at night...they really kill your night vision. I was wondering if there was anyway to dim the output of the LEDs in the guages... Would installing a resistor work? -p.s. I know very little about electricity.
Even a adjustable resistor might not work. Without knowing the I-V characteristics of the LED it's hard to determine the window of voltage that you can adjust. Typically a diode goes into forward bias mode (current flow) within a very little voltage window once the "on" voltage is reached. So basically, the diode essentially has two modes, on and off. trying to use a resistor might be futile as that would have to have incredible adjustment precision to control the voltage within hundredth or thousandth of a volt. Look up diode i-v characteristics online and you'll see what i mean.
If he is right ^^^^ maybe you can get some tinting film from Alex. Kinda ghetto I know, but at least you may be able to see better at night...
He's right. Typically, variable brightness in LED's is controlled by a circuit that pulses the LED. The light is actually flickering on and off, but faster than 60Hz so that it doesn't look like a strobe. How long the light is on for and how long it is off determines the apparent brightness. Your simplest solution, as mentioned, will probably be to tint the LED. Your other option would be to replace it with a lower mcd (milli-candella) rated LED. (Good opportunity to change the color too.) I did this on a USB hub I installed in my dash for my CarPC. The blue one that came with it was hella bright, so I replaced it with a dimmer green to match my gauges.
well, as i remmber when i took EE. Messing with LEDs.. even with a small resister light output can be drastically reduced.. if you dont believe me.. get a LEG.. a a small 1k or 2k resister.. power up the LED with no resistor then with 1 then with 2k.. BIG diff.
The LED will draw 2.0V and the resistor will draw 10V, leaving you with 1/6 of the power you had going to the LED before. depends on how complicated you want to get. you can get a 7805 voltage regulator, a PNP transistor and a 10k potentiometer. hook 12+V to pin 1 on the 7805, pin2 to the collector on the transistor, and the base of the transistor to the wiper on the potentiometer. pin3 of the voltage regulator goes to your diodes..... yea... i'd just put some black film over it.
Hey alright! The little studying that I have done about LEDs led me to believe what you guys confirmed...that there was not too much I could do about it. The guages are already pretty heavily tinted...I'll check out some darker tints. On the other hand, I am seriously considering getting rid of these things and going back to my auto meter sport comp mechanical guages...it is too bad, because they work great, and look great...just WAY to bright.
IIRC with the prosports, the circuit that drives the LEDs also drives the sensor input, so messing with it with adversely affect the gauge reading. only bad thing about gauges with sending units like them. if they were cheapo autometers with a lamp, you could do it quite easily