Hello everyone, I'm new to this forum and I've spent some time trying to read through it. I found a couple discussions that are close to what I'm looking for but nothing right on so I decided to make a post.
I'm looking to take some 12 volt accessory vehicle lights, the typical 6-in rubber grommet mount lights and and put anywhere between 4 to 12 of them in a row to create a light bar that has strobe effects. I have an Arduino Uno and I currently am able to do this effect with regular single LEDs but the problem I run into is when I jump up to the 12 volts, I understand I can't use the Uno to control these larger 12 volt LED lights. From what I've read so far it appears I would be able to use a MOSFET of some sort to be able to act as a kind of like a relay to turn on 12 volt power. I was wondering is there anything of concern because I would be doing a strobing effect. Depending on some of the different patterns the shortest on-off periods probably will be around 50-75 milliseconds.
Again, I know they make light bars similar to this but I just think it would be fun to be able to make my own and then create any type of pattern I want. I'm not necessarily worried about it being easier or not to just buy one. It's mainly for my tinkering and educational purposes. Below I attached the screenshot of a type of light that I was thinking of using. It has two brightnesses. I was probably just going to use the brighter setting as the strobe setting and maybe down the road. If I can get that to work I will mess with the two different brightnesses.
You'll need one Arduino output pin and one driver for each separately addressed light. (There are ways to "expand" the number of outputs.)
Experiment with one driver & first. Or, maybe just try a switch to see if you can blink-on for a fraction of a second. These things have a built-in constant-current driver and you can't predict how they will react to being quickly switched on & off.
Incandescent lights are more predictable, but of course they are less efficient (they require more current) and they don't flash-on instantly. They take about 100mS for full-brightness and a bit longer to dim-out.
That makes a lot of sense with just trying one. Is there any particular mosfet that you think would be good? I'm new to using them. Obviously it appears in N channel but I'm not sure if there's a particular model number that would be the best.
No problem, it is very good at that and inexpensive if you use a MOSFET driver. When starting pick a MOSFET that will support a lot more current then you need, 20A or so is no problem and does not cost that much more. Nice part they are generally in TO220 packages making them easier to work with. There is a parameter called Vgs, (Voltage gate source), this determines how enhanced the MOSFET is (On Resistance). Pick something with less than a 3V rating if you can find one.
Blinking light bulbs causes early failure because of thermal fatigue. LEDs do not suffer that and are very fast turning on or off and much less heat.
