Well, starting to mock up the circuit I going to use in making my own turn signals. I decided it would be fun to make my own: electrical and mechanical.

Couple of pics of just the test circuit for the front signals. First one is running light brightness, second one is turn signal brightness.




I've started the layout of the printed circuit boards, and have the right front done. Just to 'mirror' it for the left side. I wish it was that easy

I've got the shells of the turn signals done in rough draft, now I need to do some finalizing of the drawings and decide whether I'll do the fab work or have it done for me. I would like to build the fronts out of stainless, but it's been a while since I've welded SS, and I'm not sure my little TIG will handle it.

 

E = i x r

I'm still trying to get mine to blink.

 

So the stock bulbs pull .5A each on the running light, no big impact when running LED lights, you're just pulling less current.

The turn signals are a different matter, because you have to pull similar current for the stock turn circuit to work. The stock turn signal bulbs pull about 2A each. This is where the "equalizers" come in, in the kits that are sold. The new circuit needs a separate load resistor, in parallel with the rest of the circuit.

 

Thought I would add an update.

I've got my second stage mockup complete and checked out. This mockup board has the same number of LEDs I want to use, and the same LED part numbers:





The auto brightness of the camera in taking still images, does not show a good compare between the running lamp circuit and the turn signal circuit... but there is a big difference. Video below shows it better.

The small blue device at the bottom of the board is called a 'trim-pot'. It's a variable resistor that I installed, so I could vary the turn signal current through the LEDs, and basically 'dial in' the right resistor setting.


I mocked it up on the bike today to compare it against the stock turn signal. I think it will work just fine. I'll see if the video will paste in here:



I had the bike running, because the voltage just sitting there is just under 12v. Voltage while running at idle was 14, and I wanted a good representation.

 

Archer, that's excellent. I've had a little circuit training but it was more than 12 yrs ago. I've forgotten most of what I learned. I remember enjoying building circuits from scratch as you are doing.

 

Cool, thanks! I could probably take some other pics of the mockup board and explain a little more what I'm doing, like: setting the current for idle and turn, protecting the bike's circuitry with diodes and a shot of the mockup 'equalizer' that makes the LED board work just like a bulb in the stock system..... if anybody is interested...

 

Have at it. I'm sure someone would appreciate it.

 

This is the shot of the schematic, which I did right after choosing the LEDs I wanted to use.



I got the "TS" and "RL" labels backwards.... doh!... anyway....

I chose the LEDs based on luminosity, forward voltage, current and color. Once I knew what forward voltage they required, I knew how many I could put in a series string for a 12 volt (11.95-14.0) system. The amber LEDs I chose are 2.1v, and the red are 1.7. To keep my circuits similar front and back I decided on a string of 5.

The amber LEDs have a luminosity of 1000 millicandela at .02A, and a forward voltage of 2.1vdc.
The super red - 1500 millicandela at .02A, and a forward voltage of 1.7vdc.

These are fairly bright LEDs. I could have gotten brighter, but then the cost starts to outweigh the fun

The diodes D1 and D7 are to protect the bike's electrical system. They will prevent any voltages and current from going back up that particular part of the circuit, so the running light voltage will not be seen at bike's turn signal circuit, and visa versa.

 

Archer, an explanation would be awesome. It's been a long time since I've studied circuits too and maybe the details would help stimulate the old thinker!

 

I then went and got some supplies from the neighborhood electronic store: a breadboard to build proto circuits on, a few packs of common value resistors, diodes and a couple of pre-fab circuit boards.





This allowed me to create the circuit for the single strand of 5 LED, that would just be duplicated then.

The values I chose for components were based on the rating current of the LED. To attain .02A (20milliamps) in a 12volt system requires a 600 ohm resister capable of dissipating 1/4 watt.
(resistance = voltage divided by current) (power = voltage times current).

So I chose several values around those, and got resistors capable of 1/2 watt. It's always good to have plenty of room in the specs department