LED dash lights...

[Chuck Leeper]

With more add-on gauges being lit w/ LEDS, original dash bulbs being converted, is there a dimmer to replace the oem rolling switch?
I just checked the oem dimmer, and it shows 200K down to 6+K ohms. This will not work w/ the LED lighting in my Autometer Cobalt model gauges.

 

[davelostmissing]

Wish I had a dimmer here to play with
We need to put a load on the rheostat and use that voltage as a reference for a variable regulator....
( I think...)

 

[davelostmissing]

I suppose we need to anticipate a mix of LEDS and bulbs on that dimmer?

 

[Chuck Leeper]

I suppose we need to anticipate a mix of LEDS and bulbs on that dimmer?

We, [Hot Muscle Wiring], are experimenting w/ a load across the oem dimmer. Missed the first time, and fried the resistor.
I'd guess some folks will have a combo. I'm considering all LED liting.
My 86T will have all LED, once it's done. I may swap them out on the 87T, also.
The Autometer catalog shows one. Not real $$. Bout $35 at Summit. Don't know if it handles incan and LED combo.
We are a Autometer dlr... May buy one, see how it works. Would prefer to do a work around, so the original dimmer still works.
I have 3 of them...The first 1 we tried, w/ the heat sink, had the board cracked, and was junk...

 

[davelostmissing]

The problem is that the characteristics of the two are so different. Not insurmountable, just requires some thought.

 

[davelostmissing]

Took some measurements, I'll try my first kick at the can this week.

 

[Chuck Leeper]

Took some measurements, I'll try my first kick at the can this week.

We did too...the rheostat we tried, obviously did not have the capacity, and we "let all the smoke out"...

 

[GNVenom]

Really only one way to dim an LED. You need a PWM circuit that pulses at maybe 300Hz, and narrow the "on" time to dim the LED.

Reducing power to the LED will only cause the dispersed beam to narrow, and the color to shift. IT won't look right.

 

[Chuck Leeper]

Really only one way to dim an LED. You need a PWM circuit that pulses at maybe 300Hz, and narrow the "on" time to dim the LED.

Reducing power to the LED will only cause the dispersed beam to narrow, and the color to shift. IT won't look right.

John, thanks for the "education"!!
Guess that's why my first attempt "went up in smoke"!!
That makes me think that there must be some little "trik piece" in the dimmer that Autometer sells.

 

[davelostmissing]

Shoot me an address Chuck, I have something for you to test.
dave

 

[GNVenom]

For all you hackers out there, here's an inexpensive way to control your LEDs:

http://www.ebay.com/itm/DC5V-24V-12...727341?hash=item3a8e9c8c2d:g:0BIAAOSw3xJVd5tt

They work nicely, you can dim the lamps without losing the pattern.