DownrangeFuture
Electronic Repair Genius
Okay, so I've been looking at integrated/LED tail lights and my complaints are always that they're stupid expensive, or you don't know just how good the components are, and build quality is suspect 'cause you're buying it from some guy in China off fleabay. So I think to myself, "Self, you solder components and dissect schematics for a living. Surely, it wouldn't be too hard to build one yourself."
So I designed one. I was that bored at work.
I decided that I needed some sort of voltage regulation. Most of the ones I've seen (even the $150 ones) seem to be lacking in that area. While the voltage shouldn't change, anyone who has worked in electronic repair for more than 5 minutes knows that weird stuff happens. I also wanted a simple way to make them integrated. I was keeping the red lens so I'm just flashing that side on and off.
Anyways, here's what I have designed so far. The diagram is 4.5"x1.5" and should fit in my tail light right in front of the reflector. I haven't nailed down the exact outside shape, but since they'll cut whatever shape for free, and I haven't decided on a professional PCB or a radio shack special. I figure that's good for now.
And for you nerdy types, here's the scat I'm working with. I think that the voltage coming in might be negative, if so the transistors would have to change to PNP type, and the collector and emitter would swap. Ground would be on the collector then. LED's are white 140deg/3.4Vdc forward/20mA. Resistors are all 10ohm @ 0.25W. Transistors are TIP29A the TI PNP equivalent.
Anyway, anyone see any issues with building this? Mostly on the schematic/wiring side. I know I could wire this up.
EDIT: I caught a big one. I calculated this at 24VDC for some reason. It should be 12. The regulator would make the voltage stay at 12 with the brake on, but would allow the current to increase. But without changing the resistance in the circuit, it won't change the current draw either way.
Back to the old drawing board.
So I designed one. I was that bored at work.
I decided that I needed some sort of voltage regulation. Most of the ones I've seen (even the $150 ones) seem to be lacking in that area. While the voltage shouldn't change, anyone who has worked in electronic repair for more than 5 minutes knows that weird stuff happens. I also wanted a simple way to make them integrated. I was keeping the red lens so I'm just flashing that side on and off.
Anyways, here's what I have designed so far. The diagram is 4.5"x1.5" and should fit in my tail light right in front of the reflector. I haven't nailed down the exact outside shape, but since they'll cut whatever shape for free, and I haven't decided on a professional PCB or a radio shack special. I figure that's good for now.
And for you nerdy types, here's the scat I'm working with. I think that the voltage coming in might be negative, if so the transistors would have to change to PNP type, and the collector and emitter would swap. Ground would be on the collector then. LED's are white 140deg/3.4Vdc forward/20mA. Resistors are all 10ohm @ 0.25W. Transistors are TIP29A the TI PNP equivalent.
Anyway, anyone see any issues with building this? Mostly on the schematic/wiring side. I know I could wire this up.
EDIT: I caught a big one. I calculated this at 24VDC for some reason. It should be 12. The regulator would make the voltage stay at 12 with the brake on, but would allow the current to increase. But without changing the resistance in the circuit, it won't change the current draw either way.
Back to the old drawing board.
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