Elenco Green Projects - Manual (Page 47)

-46-
Setting the time on the clock (T2):
• Press the left button to select what to change
(month, date, hour, or minutes).
• Press the right button until it is correct.
• Press the left button until the time is showing,
then press the right button once to start.
• The colon (“:”) will be flashing when the clock is
running.
• Press the right button to display the date.
Project #68 Cola Clock
Cola Clock with Memory Project #69
You could also use a battery for electricity storage instead of the capacitor. A
battery stores much more electricity than a capacitor but you don’t need much
storage here. Batteries are much more expensive than capacitors and contain
chemicals that can harm the environment when you throw them away.
In the preceding Cola Clock project, when
you disconnect the liquid energy source to
replace the cola, the time is lost. Wouldn’t
it be nice if the clock remembered the time
long enough for you to replace the cola?
Add the 470 μF capacitor to the clock as
shown here. The capacitor stores enough
electricity to run the clock for a while if you
disconnect the liquid energy source.
Don’t drink any soda or juice used in this
project. Wash the electrodes and liquid
holder.
Assemble the liquid energy source using the instructions on page
4. Connect it to the clock (T2) with the red & black jumper wires, the
red wire goes to the copper electrode. Fill the compartments with
cola soda (other soda flavors and lemon, tomato, or grapefruit juice
also work). The clock should be running. Set the time if you like.
With cola, the clock will typically run for a week. When the display
gets dim, replace the cola.
You can move the copper electrode with the snap on it over to the
next compartment, as shown in the Liquid Battery project. The
clock display will not be as bright now.
If the copper and zinc electrodes get corroded through use, use sandpaper,
steel wool, or a scraper to remove the corrosion and improve performance.
Don’t drink any soda or juice used in this project. Wash the
electrodes and liquid holder.
The clock needs very little electric current to operate (much less than 1mA).
The liquid power source does not produce much electricity, but it can supply
enough for the clock. Slowly, the chemical energy in the cola is used up, and
the voltage drops enough for the clock to stop working.
+
Liquid Energy Source