You are using 6V. You should use 2 LEDs with 150 Ohms (better) or 3 LEDs with 50 Ohms in series. As voltage decreases, it can no longer support 5 LEDs in series. And after doing this, do not test with 12V. Use only 6V from bike for testing. Diodes, Capacitor remain the same.


Keep the LEDs as close to the red plastic cover as possible.

what is the difference between the diode IN4007 MIC & IN4007 DC
earlier i have used IN4007 MIC which is working fine ,

for 16v capacitor is 170 ohm resistance is ok for 5 L.E.Ds or should i go for 200 ohm

All gone fine until I fit it into the bike's tail light. After fitting it I noticed that the lights dont have enough brightness, (RX100 is 6v) and there is no park light. I removed it, replaced all resistors with 100 ohm, and checked the whole circuit again and again, whole thing working fine.

Back inside the tail light box, break light is now more bright, but still there is no park light and the second column from the right doesnt have enough glow. I checked all the wiring again and again, park light circuit working fine when i connect to an external power supply. But not working with the bike's power supply, I checked the bulb holder, It is working fine, checked the old bulb that i broke and connected the wires, it's too working fine. But no park light. Somebody please help me on this.

change the L.E.Ds which are not bright, i did so & this problem was gone
you use 1000mf ??v capacitor so you may need more resistance to save the L.E.Ds
& how did you checked the ckt at home by providing 12v ac

i have changed the diode, capacitor but still when i rev the scooter the L.E.Ds blinks & goes off

I used 1000uf, 25v cap.
then what is the ideal capacitor value?? I used my Creative SBS 2.1 speaker's power adapter for 12v AC. For DC supply i used my broadband modem's power adapter.

another weird thing is, The RX 100's tail light lens has a prism like pattern in the center region. so the LED's light not fully coming outside. It's ok at the sides where i placed my park light LEDs.

change the L.E.Ds which are not bright, i did so & this problem was gone
you use 1000mf ??v capacitor so you may need more resistance to save the L.E.Ds
& how did you checked the ckt at home by providing 12v ac

i have changed the diode, capacitor but still when i rev the scooter the L.E.Ds blinks & goes off

Hi guys, recently I decided to replace the bulb in the tail light of my bike with LEDs. The procedure I followed is described below. Hopefully it will help someone else contemplating making the same mods.

Here is a pic of my bike



First, I have created a circuit board in the shape shown and mounted the LEDs. I used 10mm Red LEDs. The LEDs were soldered as per the circuit diagram. Diode used is 1N4007. Capacitor is 1000uF. Resistor - 200 Ohm.









As the parking tail light runs on AC, so used a bridge rectifier circuit to convert to DC. Capacitor is needed to reduce flickering. Now, I did not want any wire slicing. So used the old bulb to power the LEDs as shown..







The final product looks like this.



I am sorry that I have only one snap of the final tail light at the moment. Also this snap does not show the brake light. Only the parking light. Also at night, the number plate is covered with a cool red glow! I can upload further snaps as and when I click.

Similarly, I have also used white LEDs in the meter console. The while LEDs combined with the green screen found under the dials combine to give a cool teal colored glow! But this time, I forgot to click snaps while opening the console and fitting the LEDs!



I will be happy to answer any doubts regarding the mods.

Now, the reasons for doing all this? Agreed, the LEDs look cool. But I wanted to save power. LEDs consume hardly anything - each LED consume 40 milliwatts. The tail light consumes 5W, brake light - 21W and meter console lights - 3W X 3 = 9W. But as the brake light is not on continously, I save atleast 5W + 9W = 14W. Also, I have removed the front pilot light. So, total 19W saving. So for what purpose? To install a powerful headlight instead of the present 35W comfortably. After the mods, I can now easily install a 55W light without any strain on the alternator.

I will be shortly installing a new headlight. But, I recon I need to change the reflector too. Can you guys suggest which reflector to use? My bike is the old model P150 with round headlamp. I preferably want a direct fit. (Maybe Ambassador silbeam or maruti omni, maruti gypsy, trucks etc)

P.S. - All snaps were taken using my MotoROKR E6.