Here is such a funky LED backlight for each bike you can make with your own hands. There is no trick, but the result exceeds all expectations.
In fact, I had long dreamed of such a backlight, but I could not afford the purchased devices, and in principle, and not only to me, it was expensive and stupid! But once, a straw from a cocktail fell into my hands and I immediately stuck a 5 mm LED into it. LED sat like a glove! Next, my brain invented a method of mounting on wheels and a method of transmitting electricity!
1. LEDs of increased brightness (color to taste), with a diameter of 5mm. - the amount at your discretion, I took 18 pieces of 9 per wheel. 2. resistors by the number of LEDs. 3. shrink - 1 meter 4. assembly wire - 1 meter 5. foil-coated fiberglass ~ 120x120mm - 2 pcs. 6. clamps (couplers) of 100 mm - 1 unitary enterprise. 7.4 batteries (AA)
In the auto parts store: 8. generator brushes for VAZ 2101 - 2 pcs.
In the food: 9. cocktail tubes by the number of LEDs
Getting started assembly
In the resulting tube, insert the LED and the plug.
Before you insert the LED into the tube, you need to modify it. The fact is that the LED is not round, but has a cone and a protrusion at the very bottom. And tightly such an LED can not be attached to the needles!
What to do ? - It is necessary to make a cut with a file on the diameter of the spoke. See picture.
Now about the stubs. I took a piece of aluminum wire with a diameter of 5 mm. and long enough for fastening by a collar. In general - you can use the second LED, then it will be even brighter! Our plug must be put on sealant or on glue like "moment"
When installing the LED, problems may arise: the straw may be smaller in diameter! And for this it needs to be expanded. For example, with a pencil or squeezing quietly in a vice.
So - our "neon" is ready! It is necessary to calculate the resistor. The resistor R is determined by the formula: R = (VS - VL) / I
VS = supply voltage VL = forward voltage calculated for each type of diode (usually 2 to 4 volts) I = LED current (for example 20 mA), this should be less than the maximum allowable for your diode. If the resistance size cannot be selected exactly, then take a larger resistor. In fact, you are unlikely to notice a difference, the brightness of the glow will decrease very slightly. For example: If the supply voltage VS = 5.15 V, and there is a green LED VL = 3.5 V, requiring I = 20 mA = 0.020A, then R = (5.15 - 3.5 V) / 0.02A = 82.5 Ohm. In this case, you can select 100 Ohms (the closest standard value, which is larger). After we calculated the value of the resistor, you can safely purchase and solder it to the leg of the LED.
Mounting brushes. The brushes will have to be fixed in place, because different models of bicycles have a diverse geometry and a number of additional holes. You will have to solve this problem yourself. I can only advise that the closer the brushes to the axis of the wheel, the better, this helps to reduce the diameter of the current collector disk.
At the very worst end, you can install the batteries on the wheel closer to the center, thereby abandoning the brushes, but this operation is at your risk.
Current collector. A foil-coated fiberglass, approximately 120x120 mm, will be required. See the photo.
it is best to mount the current collector neither the disc brake (if any), it has a ready-made mount on it, with screws.
As batteries, I used 1400 mA / h Ni-MH batteries.
The holder can be taken from the rear seat post reflector and attach a pad of PCB to it with screws.
We glue the battery box to the site.
For the symmetrical distribution of the tubes on the wheel, we install them on the one hand, during operation it is generally imperceptible that they are on the side.
We fasten the LED tubes with ties (clamps) for the plug and LED. Please note - the coupler lock is on the spoke. We cut off the extra tails of screeds under the castle root with side cutters.
The scheme of the device.
As luminous tubes, you can use not only straws. For example, my friend used dropper tubes filled with glitter gel, which was also quite original.
Have a good night racing!