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What is a Resistor?
A resistor is an electrical device (usually composed of a passive material like carbon) that limits
the flow of current and voltage from a power source. Resistors are important components in any
electrical circuit, since other components that are connected to the resistors depend on the
limited current and voltage they produce to operate correctly.
The physical part and electrical symbol for a resistor are shown below:
What is a Capacitor?
A capacitor is a device that stores energy from a power source and then releases the stored
energy when it is no longer available. It is somewhat like a rechargeable battery, but quite
different in terms of its construction and use in circuits. Depending on the size of the capacitor
(its value, in units called Farads), it can store and release energy many times faster as compared
with a battery. The experiments will use the capacitor to "filter" or smooth out the voltage "ripples"
produced by the wind turbine.
Capacitors come in two basic types – polarized and non-polarized. A polarized capacitor requires
that you connect the positive lead to the red terminal on the circuit board and the negative lead to
the black terminal. Non-polarized capacitors can have either lead connected to positive or
negative. The experiments only use a polarized capacitor.
The physical part and electrical symbol for a polarized capacitor are shown below:
The longer lead of a polarized capacitor is positive (+) while the shorter lead is negative (-). The
negative lead is also identified by a series of bar-and-arrow symbols on the part itself. In the
experiments that follow, be sure to observe the positive and negative portions of the capacitor.
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