Bicycle tail light circuit schematic

Hello,

I was wondering if anyone has the internal circuit schematics of any of the popular bicycle tail lights. I am trying to find out how these lights have been powered, most have just one push button that can turn on/off, blink and give constant light. How has this been done. I would like to create my own bicycle light (due to a shortage of funds) and need an idea of how that is managed in lights that are in the market.

Please post any pictures you may have of opening up your bicycle tail lights so that the internal circuit is visible. Thanks a lot.

Buying a good tail light will cost you less than building a light on your own.
http://www.amazon.com/dp/B000RYAKHC/?tag=cpf0b6-20

most of the battery powered tail lights use a proprietary integrated circuit that is not available for purchase separately.

If you want to make a flashing LED light, one option is to use the LM555 oscillator circuit with an external transistor to drive the LED(s).

http://www.ti.com/product/lm555?keyMatch=lm555&tisearch=Search-EN-Everything

I wonder if Radio Shack still sells these? Otherwise, Jameco, Mouser, Digi-key and others sell them, as well as resistors, caps, transistors, etc.

LEDPowered said:

Hello,

I was wondering if anyone has the internal circuit schematics of any of the popular bicycle tail lights. I am trying to find out how these lights have been powered, most have just one push button that can turn on/off, blink and give constant light. How has this been done. I would like to create my own bicycle light (due to a shortage of funds) and need an idea of how that is managed in lights that are in the market.

Please post any pictures you may have of opening up your bicycle tail lights so that the internal circuit is visible. Thanks a lot.

Click to expand...

You are obviously asking about battery rather than dynamo lights. The easiest way to replicate the single button toggling between different modes that you are asking about would be to simply buy a suitable flash-light driver circuit board from DX or similar and wire it up with power supply and LEDs as appropriate. Most of these commercial 'toggle mode' lights use a similar sort of logic board arrangement. The most expensive can actually be programmed by the user for different modes but most just toggle between off-steady-one (or more) flashing modes!

To replicate something simple such as the PBSF you need to start with some idea of what battery supply you are going to use and then what LED array you want to drive. For a tail light you do not necessarily have to use a power-LED although it can be spectacular if you do. There are good arguments for simply using an array of 5mm lower-power devices, easier cooling being one! There's a great deal of discussion about this from past threads, notably the legendary 'running light' discussion from a couple of years ago (the pictures alone are worth the visit!) Someone should be able to provide a link. If you just wanted simplicity Steve's 555 suggestion is probably the way to go. Also discussed at the Running Light thread if I recall right.

Sam