The presentation will now discuss capacitors used in filtering applications. Filtering capacitors are used to do one of two things, either to allow a certain signal to pass through, or to block DC voltages. One inherent characteristic of a capacitor is its impedance (or resistance), which changes as frequency changes. For low frequencies such as DC or a battery, a capacitor will have high impedance and will block the voltage, while at higher frequencies a capacitor will have low impedance and allow the voltage to pass through easily. This behavior can be beneficial for the circuit designer and the use of capacitors for filtering application is widely accepted. Noise filtering is a common application as many of today’s electronic circuits require noise suppression circuitry. Modern electronic systems have requirements to reduce or eliminate unwanted noise from getting onto the power line. In addition they are designed to be able to withstand a certain amount of noise on the power lines and still operate correctly. It was not very long ago that a television would have static on the picture when a hair dryer or microwave oven was turned on. Today’s electronics do not generate as much unwanted noise and are also more forgiving of noise than electronics of the past.