Hey guy,
Thanks for all the replys.
Here is exactly what I am doing. Some of you may remember my traffic adviser project.
https://www.electro-tech-online.com/threads/finished-traffic-advisor-project.33618/
Well, I am making version 2.0. This one needs to be a little bigger and brighter. So bottom line, I need 4 of the luxeons per section. So whatever regulaton design I settle on, I need atleast 8 of them if not 16 (assuming I can't get all 4 LEDs in series)
Thats what kinda steered me away from the easy route of buying a driver like the one Harvey posted. Along with the already pricey Luxeons, adding the drivers would make this too expensive.
The issue with the brightness changing is not a huge issue. Atleast i don't think it will be. I don't have the luxeons yet to play with, but the 5mm orange leds I do have don't change in brightness enough to bother me +/- a few volts/mA.
40v spikes? Wow. Thats somthing I didn't know.
I was going to add a crowbar circuit in the control circuit for the lights. Would that be fast enough to prevent damage in an automotive setting?
Now I am wondering what kind of spikes the electrical system of my truck sees. Its an older diesel truck, with no ECM or any computer controls, so i suppose the regulation could be pretty sloppy. It also has grid heaters that cycle to warm the air intake when its cold. They switch a huge load on and off the system.
I wish I had a hand held scope so I could watch as I drive around.
I suppose I could try it with my desktop scope in the driveway. Switch the heater fan, headlights and grid heaters on and off and see what happens.