While cruising the internets for cool things people do with commuter bikes I ran into a very neat product from England. Its made by a company called Bicygnals. Its a nifty light assembly that contains headlight, tail light and turn signal LED’s. I was pretty impressed and have thought for a while that bikes should have more options for indicator lights rather than the simple ‘look out - I’m here’ lights. In my hunt I have found nothing that I feel is compact and clearly communicates your intent as a driver/rider on the road. I think its a bit of an improvement to have a series of 16 LEDS that will sequentially blink to indicate a direction rather than have a set blink on the right or on the left. Frankly, as small as a bike is, the turn signals that are available seem indistinguishable right or left, maybe with the exception of the Bicygnal front module. If you don’t know what I mean pay close attention the next time you come up on a highway patrol car on the side of the road from behind. The bright orange lights that blink and give the illusion of the lights steering you in the desired direction. Some big trucks use this, you can’t mistake the intention of the lights.
Considering what the commercial products cost and don’t really deliver I started thinking about making my own sequencer for the bike. Plus, I like the idea of a brake light too! With LED power consumption what it is, you can have it all on a pedal powered machine. I could power it with any number of power cell or battery options. I just need a circuit. I am no circuit designer, save the simpler stuff, but I can work with something someone else has made. Google tracked down a good sequencer for me and I wanted to share it with any of you that have read this far.
Credit where credit is due: I found this write up HERE
Expandable 16 Stage LED Sequencer
The circuit below uses a hex Schmitt Trigger inverter (74HC14) and two 8 bit Serial-In/Parallel-Out shift registers (74HCT164 or 74HC164) to sequence 16 LEDs. The circuit can be expanded to greater lengths by cascading additional shift registers and connecting the 8th output (pin 13) to the data input (pin 1) of the succeeding stage. A Schmitt trigger oscillator (74HC14 pin 1 and 2) produces the clock signal for the shift registers, the rate being approximately 1/RC. Two additional Schmitt Trigger stages are used to reset and load the registers when power is turned on. Timing is not critical, however the output at pin 8 of the Schmitt Trigger must remain high during the first LOW to HIGH clock transition at pin 8 of the registers, and must return low before the second rising edge to load a single bit. If the clock rate is increased, the length of the signal at pin 9 of the Schmitt Trigger should be reduced proportionally to avoid loading more than one bit. The HCT devices will normally provide about 4 mA (source or sink) from each output but can supply greater currents (possibly 25 mA) if only one output is loaded. The common 150 ohm resistor restricts the current below 25 mA using a 6 volt power source. If the circuit is operated with two or more LEDs on at the same time, resistors may be needed in series with each LED to avoid exceeding the maximum total output current for each IC of 25 mA. For greater brightness, individual buffer transistors can be used as shown in the 10 stage LED sequencer on this same page.
