Data Sheet

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111. Capacitor Basics
Build the circuit shown on the left, connect points A and B with the
spring wire (9), then turn on the switch (62). The heart LED (69) will
light and then fade out as the 470mF capacitor (74) is charging.
Remove the spring wire (9) from points A and B and place the spring
wire (9) across points B and C. You will see the bi-directional LED (71)
light red for a while and fade to be very dim as the 470mF capacitor
(74) discharges.
Capacitors are made of two plates separated by an insulating material
between them. When a battery or voltage source is placed across the
leads of a capacitor, one plate builds up a positive charge (like a build-up
of a holes) while the other plate builds up a negative charge (build-up of
electrons). Once charged, even when the voltage source is removed the
capacitor will maintain its build up of charge until connected to a circuit
where the charge build-up can be discharged through a resistance.
112. Capacitance
Reverse the direction of the bi-directional LED (71) in the previous
project. Connect points A and B with the spring wire (9) and then turn
on the switch (62). The heart LED (69) will light red and then fade out
as the 470mF capacitor (74) is charging.
Remove the spring wire (9) from points A and B and place the spring
wire (9) across points B and C. You will see the bi-directional LED (71)
light blue for a while and fade to be very dim as the 470mF capacitor
(74) discharges.
Capacitance is a measure the capacitors ability to store energy. There
are three primary factors that determine the capacitance of a capacitor:
the size of the plates, the distance between the plates and the type of
insulating material (called a dielectric) placed between the plates.
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