Letting My Geek-ness Show

June 16th, 2008 John Posted in Commuter Bike, Engineering, Fun, Geek, Technology, Transportation 1 Comment »

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.

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Energy | Third World Generation Solution?

October 18th, 2007 John Posted in Engineering, Environment, Science No Comments »

People are always looking for ways to do things like purify water or generate electricity in a smarter, more efficient way. One advantage to this quest is that new technologies can be used in impoverished areas of the world to help raise the standard of living in those places. Well, I Stumbled this little video from Popular Mechanics and was impressed with the ingenuity. I would like to see some more discussion revolving around scalability. That being said this is fun, you could probably build one yourself!

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Science | Beaming Energy Down From Orbit

October 17th, 2007 John Posted in Engineering, Environment, Science No Comments »

These are the kinds of stories I like: sending up an array of solar panels that will collect pure, unobstructed solar energy and then beam it down to a relay station on the surface of the Earth. It has its technical and political challenges, but its a little bit of outer space fiction coming to life on a drawing board.

The good news? Beaming all the solar energy we could ever need down to Earth from space appears more feasible than ever before. The bad news? It’s going to take a lot of money and political will to get there.

Click here to read about it at Green Options.

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Engineering | Alternative Energy

September 24th, 2007 John Posted in Engineering, Environment, Politics, Technology No Comments »

In an article in Green Options, Joshua S Hill posted an interesting blog about alternative energy opportunities. His post, US Power Requirements Solved in 92 Square Miles outlines a neat idea to generate power, AC power, using solar energy to heat tubes of liquid water that will boil and create steam to run nearby turbine generators. The spokesman for the project, Ausra David Mills said at the International Solar Energy Society conference that he even had a solution for night-time solar generation. His proposal suggests that enough heat can be stored in the tubes to continue to create steam over night until morning returns again.

This engineer is excited, if a little skeptical about the night-time generation. But they are going to build a test model so I really hope that we will see an alternative to our fossil fuel-dependent energy model in the United States.

Check out the write up if you haven’t already.

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