Search all of my sites with Google

Wednesday, June 4, 2008

Lights, Camera, Action...

Well, lights, anyway. Right after the previous post I got busy with non-bike stuff again, so now I'm back with the tidbits of stuff since then. This includes pics of the red-LED replacement/additions in-progress (since there's just the video in the previous post, and the one before that covers only the amber ones). I also visited a Pull-A-Part junkyard during a half-price Memorial Day sale, and got a few parts off of various cars to use; unfortunately only one car even had any LED lighting, and it was so badly trashed from whatever wreck put it in the junkheap that I can't tell you what kind of car it used to be, except that it was Japanese (since it was in that section of the yard), and red. Since it had a nearly-intact 3rd brakelight in what was left of it's airfoil bar above the remains of it's hatchback, I pried that out and bought it, and used it intact as my brakelight (since I haven't had time to take the lights apart again and finish the actual brakelight the way I wanted to).

This is just a snapshot during the process of replacing the amber LEDs with red ones, for the side markers in the rear. They're so bright that the camera barely picks up the room's 4x 40w fluorescent tube lighting of the countertop the module is sitting on.

This is that third brakelight unit, ziptied above my ex-scanner-nee-lighting module.

The left pic is with the camera flash on, and even in that you can still see the lights--I didn't modify the car's module at all--it's just a completely transparent sealed plastic unit with 9 LEDs, which are just about as bright as the LumiLEDs I used for the taillight, though they are a different shape (and probably manufacturer). The 3rd brakelight module was made by Stanley--dunno if it's the same Stanley that makes tools and automatic doors and whatnot. Interesting maker name for a part off a Japanese car?

These are some pics of the front marker/signals, which are amber, and which do not alternate like the rear ones--these just change brightness by about 1/2 during signalling; it simplified things in front, since I only needed one color (as opposed to the red rear side markers plus amber rear turn signals).

It's supposed to blink on and off completely, but the way I designed it to flicker, I just have a 2n2222 transistor wired with it's collector at +V (as are the LED string anodes) it's emitter connected to the LED string cathodes and the current-limiting resistor for the strings, with the other end of that resistor at ground. The turn signal generator (module out of that scrapped electric scooter) provides the base a positive-level signal when it's activated, which is supposed to force the transistor to short across the LED string and pass all the current directly thru the resistor. Since it's short enough durations, it won't hurt the resistor or transistor, which do get warm but not hot. Unfortunately, the transistor apparently can't pass enough current to pull *all* the power out of the LED strings' signal path, so I either need a larger transistor, or a different circuit (I used this one because it's the simplest one I could use that would not be wasting power and a voltage drop on that transistor *except* when it's in use--I didn't want to run power thru it all the time).

No comments:

Post a Comment

Alternate suggestions or improvements to anything that's been posted is very welcome, and extreme detail is preferred to brevity.

Keep in mind that unless you leave an email address in your comment, I haven't any way to reply to you except to reply to your comment here. That means if you want a reply, you'll have to come back to *this* blog entry and it's comments to see my reply to you, unless you leave some method of contact within your comment.