Bicycle Led Light

Many times. I used the bicycle in the night and I dont have a lights!. So i decided a make a circuit that blink leds with few components and also very easy.

I also want the light, once installed, to be invisible and the back part of the seat offered a small space

I have 2 retroreflectores so I decided to use the biggest one that allows me to leave the pcb embedded and it is also red!

since my goal was to use few components, use a ne555 ic as a hysteretic oscillator with which I achieve approximately 7 Hz. I used a 555 ic because works with low voltages like those of a li-ion battery.

I used the following materials:

• ne555 smd
• 1 10k resistor 0603
• 1 10uF 6.3v capacitor
• 5 red led 0805 smd
• 5 220 resistor 0805
• 1 old battery from smartphone
• 1 small pcb 1x2.4 in

I had never made a circuit with smd components, first soldered the LEDs and their resistors and then the ne555 ic, the 10k resistor and the 10uf capacitor.

Finally, solder wire to the pcb.

solder some connectors to the wires of the battery and the pcb.
just need to close the circuit, will it work?

it works! :D

just remain install all it, the pcb and the battery.

the pcb hold it at pressure by the retroreflector.

the battery is hold it with 2 zip ties to the back of the seat

the led light finished and running in the bicycle.

I did not use any switch so when I do not use it, I disconnect. But it would be a good idea to place a switch to avoid connecting it backwards and damaging it.

The pcb in principle I did it with a marker, but then I made a pcb in eagle that is seen in step 2, here is