Editing BicycleLighting
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The photoresistor registers about 140k ohms in inside natural light, held under the bike seat. In the bathroom with the door mostly shut, simulating nighttime, it registers 22M. Tentative initial ON value: 20Mohm. | The photoresistor registers about 140k ohms in inside natural light, held under the bike seat. In the bathroom with the door mostly shut, simulating nighttime, it registers 22M. Tentative initial ON value: 20Mohm. | ||
Learned a bit of comparator chip circuit theory from David... Have the op amp circuit breadboarded out such that it turns on one LED when the photoresistor is occluded | Learned a bit of comparator chip circuit theory from David... Have the op amp circuit breadboarded out such that it turns on one LED when the photoresistor is occluded. | ||
=== next step === | |||
Update breadboarded comparator circuit to use potentiometer for calibration. Take it to light & dark places & mess with it. | |||
Still need transistor circuit as all the LEDs together will be more current than the op amp can handle. That is the last piece of circuit. | |||
Big(?) capacitor behind seat switch s/b sufficient to keep lights on for some time after seat is vacated. How big must it be? | |||
I can create the seat cover with embedded pressure switch whenever, it's just a switch, so it can wait until last. | I can create the seat cover with embedded pressure switch whenever, it's just a switch, so it can wait until last. |