Quick-And-Dirty Bicycle Lighting System

Quickie lighting system with turn signals and brake light from (mostly) scrap/on hand parts










Step One: collect the needed parts

MR-16 LED lights
LED turn signal flasher
2x LED side marker lights
LED Stop/Tail light
2x lever switches
spdt-center-off toggle switch
key switch
wire
enclosure
12v NiCd battery

Mount lever switches front and rear and link to brakes so switch closes when brake operates. Wire switches in parallel. I used switches with rollers and tied braided dacron fish line to the roller and to the brake cable (with a 'taught-line hitch' at one end to allow adjustment) - switches could also be mounted so that caliper movement operates levers...

Light can be either a bright red led light for brakes plus a dimmer red led tail light, or a combo brake/tail led light. 

(edit: pictured combo light just arrived from China - !@#$ wires enter from top *WITH NO SEAL* so rainwater can enter and turn the $7.50  blinky tail/brake light into a useless P.O.S. if it isn't sealed up before installation)

Turn signal lights may be either amber led side markers (truck/trailer side markers can be found in most any auto parts store) or motorcycle turn signal lights.

Factory-made 'turn signal flasher relays' may work (many chinese-made units*  purport to work with 0.02A (20mA or 0.24W) led lights but really require more that 10x the load) or a scratch-built 555 based flasher will work well (don't use a battery greater than 12.5v or you will let the 'magic smoke' out of the 555 timer chip).

for the prototype I re-worked a circuit board from a scrapped "mole-chaser" using a 520k  timing resistor giving a flash rate of about 1.5 times a second, transistor was a 2n2222 and relay was a Radio Shack 275-0005 9v mini relay .



*(08/30/2013) CF13JL02 type (at least the ones marked FCR:LED instead of "for LED") - 5 different samples all required a minimum lamp load of 2.5W-3W to operate in hyper-flash mode (substantially more for a normal flash rate).

FLL002 (12V-24V, 0.1W-100W) type has been reported to work ,and a MF-5 (6V-12V, 0.1W-100W) Motorcycle Flasher has been verified to work. (tested with a 14-LED side-mirror array drawing 40mA@9V)

Jiye SG252B (12V 135W) verified to work and produces an audible click from relay and has pilot led confirming operation. (tested April 2017).

One or more 3w-7w MR-16 led accent lights work well for a headlight.

I used an old 12v 4Ah NiCad pack originally intended for a video-cam I also tried a "12v 6,800mAh"  chinese battery off feebay (pack was actually a '3s2p'  (3 18650 cells in series in 2 parallel strings) that would normally be rated as 10.8v 4,400mAh as the 18650 cell is typically rated at about 2,200 mAh and the 'no-load' voltage of 4.2v drops to 3.6v under a load).

(board on battery in first pic is home-made flasher unit)

wiring is pretty straight forward: key switch turns power on and off from battery, a 'lights' switch turns on head and tail light (prototype had extra switches to turn on second and third headlight), brake switches turn on brake light...

I put the 'works' in a plastic sandwich box I had laying around and stuffed the battery in my handlebar bag. I included a smal 0-15v meter for battery monitoring and indicator lights (led with a 470-1k resistor) in the prototype