Solar Light Clock

Project Number: 81

Description: Assemble the pivot, mount the solar cell (B7) on it, and then place it next to the circuit as shown. Connect the solar cell to the circuit using the red and black jumper wires. Set the meter (M6) to the 0.5mA setting. Set the slide switch (S5) to position B. Place the solar cell in bright sunlight or near an incandescent lamp. The display on the clock (T2) should be on. Now set the slide switch to position C to add the rechargeable battery to the circuit. See if you can adjust the position of the solar cell on the pivot to make the meter measure a current. If your light source is bright enough, then the solar cell will charge the battery while running the clock. If your light source is weak, then the battery will run the clock. If you would like to set the time on the clock, see page 4.

Snappy: Solar cells are often used with rechargeable batteries, since the sun isn't always shining. Used together, the solar cell and the battery can run the clock for a very long time.