Cool Blue Running Lights

[cberkeley]

Inspired by Cherisse (my daughter), I just built two 7-LED blue striplights, using a few simple parts and a piece of PVC strip. These use high intensity Blue LEDs and are fastened to the left and right underside of the fuel tank by double-sided 3M tape. The LEDs point downwards towards the engine and roadway and illuminate the engine sides and the roadway just under the bike's midsection in a wash of Cool Blue Light. Needing a way to control it, I decided to build a simple SCR control circuit (just two inexpensive components) so that I would not need to add another switch to the bike (hey, I'm a tech-type, there's no simple way for me :-D ). Both strips powered-up draw <0.25A and they are BRIGHT!!
Turning on or "blipping" the highbeam latches the lightstrip "on" the only way to return the lightstrip to it's "off" condition is to turn off the ignition, thus resetting the SCR latch. I will document the plans over the weekend and post it here free of charge for those interested in building something similar.

[cberkeley]

BTW Here's what the SCR control module looks like:
The red wire goes to a switched power + source (tail-light or ignition sw maybe)
the brown goes to the LED Lightstrip + wires. The blue (trigger) goes to the highbeam + wire. The circuit may be encapsulated in epoxy and then housed in a piece of heat-shrink tubing.

[Jon78gs1000]

Very cool idea Cberkeley. I'll try to do this one around the whole tank.Been stripping my tank for fresh paint and Por 15,will clean free of gas and vapors and will tack weld some fasteners to the tank. This will be cool! 8-[

[HiSPL]

Groovy project... How many LED "strips" will the SCR control?

[cberkeley]

Groovy project... How many LED "strips" will the SCR control?

The particular SCR I used (2N5061) is good for 800mA so about four strips. For more lighting just use a second SCR or a single SCR rated for higher current.:-D

[cberkeley]

Very cool idea Cberkeley. I'll try to do this one around the whole tank.Been stripping my tank for fresh paint and Por 15,will clean free of gas and vapors and will tack weld some fasteners to the tank. This will be cool! 8-[

Yup!... I think it's pretty cool too.
Visited the bikeshop today and showed the owner the before and after pics of my bike and it blew him off his chair. I would like to get into refurbishing and custom bike work as a sideline. I really enjoy working on the bike in the evenings. The bike-shop guy said that there's probably a good market for such here as no one else is really doing custom work and refurbishing at the level I can go to.... they just do repairs and parts retail.

[cberkeley]

File Too Large

Groovy project... How many LED "strips" will the SCR control?

I've got a .pdf file (125kb) of the plan and tried to upload it, but its too big. Anyone got any ideas? Some of the other groups I'm associated with have a "Files" section, but I don't think such a thing exists here.

[cberkeley]

I've got a .pdf file (125kb) of the plan and tried to upload it, but its too big. Anyone got any ideas? Some of the other groups I'm associated with have a "Files" section, but I don't think such a thing exists here.

In the interim, the plan file for this project may be found in the files section of:

http://autos.groups.yahoo.com/group/BerkeleyCustomCruisers/

[mixongw]

I'm just curious as to why they draw so much current. Are they all wired in parallel? I used a 12V regulator (LM7812) and wired four LEDs in series with no current limiting resistor. The reason for the regulator is that spikes of higher voltage will kill the LED junction. If I was to wire 5 LEDs in series they could survive the spikes but wouldn't be as bright. The regulator being so close to the supply voltage doesn't dissapate that much power. It's stone cold. The 4 LEDs in series draw around 30mA. In your case, the total current would only be 120mA using 16 LEDs. The current ahead of the regulator is the same, so I'm not losing any measurable power in the regulator. The current through each LED is 30mA so the brightness is the same as wiring in parallel. The SCR is a great idea. I like the idea of not having a switch. The SCR being capable of 600mA should handle 80 LEDs.