Analog Filtering
- Page ID
- 77482
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Signals and noise are almost always expressed as electrical quantities. The electrical quantities you should be familiar with are:
Voltage
Voltage is a measure of energy available when an electron moves from a point of higher potential to a point of lower potential. The SI Unit for voltage is the Volt (V). 1V = 1 Joule/Coulomb.
Physicochemical phenomena that generate voltage include:
- Chemical Reactions, such as those that take place in a battery
- Electromagnetic Induction, such as moving a coil of wire through a magnetic field (i.e. an electric generator)
- Photovoltaic Cells, which convert light energy into electrical work
Current
Current is a measure of the amount of electronic charge flowing per unit time past a given point. The SI Unit for current is the Ampere (A). 1A = 1 Coulomb/second. Types of current include
- Direct Current (DC): Charges are flowing in the same direction.
- Here's an applet that demonstrates the production of pulsed DC:
http://micro.magnet.fsu.edu/electromag/java/generator/dc.html
- Here's an applet that demonstrates the production of pulsed DC:
- Alternating Current (AC): Charges change direction periodically.
- Here's an applet that demonstrates the production of AC:
http://micro.magnet.fsu.edu/electromag/java/generator/ac.html
- Here's an applet that demonstrates the production of AC: