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Case 94: Bill Bowden: Night Rider
Design News Staff -- Design News, November 19, 2006
To see and be seen after dark on his bicycle, Bill designed this 40-LED light. He configured a 555 timer IC to generate a continuous on/off timing cycle to alternately flash two groups of 20 LEDs. The device operates on four AA batteries, keeping things bright for even the longest night rides. You can extend battery life with a second circuit Bill designed that uses a short duty cycle to flash a single group of 30 LEDs .
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Download Bill's instructions. Scroll down to see the parts list. |
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| 40-LED Bicycle Light | ||
|---|---|---|
| Amt | Part Description | Allied Part # |
| 1 | LM555CN Timer | 263-0133 |
| 1 | 4.7ìF capacitor | 852-7070 |
| 3 | 2N4401 NPN Transistor | 431-0408 |
| 40 | Red LED | 670-1224 |
| 2 | 220 ohm resistor | 296-6306 |
| 20 | 120 ohm resistor (200 ct) | 832-0212 |
| 2 | 2.2K resistor | 296-6318 |
| 1 | 47K resistor | 296-2181 |
| 4 | Alkaline Battery (AA) | 737-0520 |
| Additional parts required | ||
| Perf board | ||
| Click here to download Bill's instructions | ||
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