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Electrical Circuits Prof. Jennifer M. Blain Christen. BioElectric Systems and Technology. Units and Scaling. http://www.powersof10.com/film http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/. Units and Scaling. Pico- 10 -12 Nano- 10 -9 Micro- 10 -6 Milli- 10 -3
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Electrical CircuitsProf. Jennifer M. Blain Christen BioElectric Systems and Technology
Units and Scaling http://www.powersof10.com/film http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/
Units and Scaling Pico- 10-12 Nano- 10-9 Micro- 10-6 Milli- 10-3 Centi- 10-2 (none) 100 kilo- 103 Mega 106 Giga 109 Tera 1012
Units and Scaling What units do we use these words with? Meters length Liters volume Grams mass Seconds time Volts voltage Amps current Watts power Ohms resistance
Resistance Opposition to the flow of charge. When we measure resistance, we measure how much an object “resists” the electrons moving through it. We measure resistance in Ohms. We abbreviate this with an Omega, written like this W.
Range How can we measure resistance? m200 1.5V 9V Ohms
Sometimes, you try to measure something too big for me. I don’t know what to do, so I show you this. Try changing the range. If you are up to 2000k, and still get this…sorry!
Voltage is a potential difference. It is measured in volts. We can think of it like the height of a hill; only the relative difference matters. Current flows from higher voltage to lower voltage.
How can we measure voltage? Volts Range m200 1.5V 9V
Electrical Current Definition: the rate of charge past a given point The more electrons that move through a wire in a given time, the larger the current. Current is measured in amperes or amps.
How can we measure current? Amps Range m200 1.5V 9V
Power The amount of electrical energy used in a given time. We measure power in Watts. We can calculate power by multiplying current and voltage. 1 watt = 1 amp x 1 volt
We are going to use wires. Remember, wires are conductors inside of insulators. We can use them to connect two things together. conductor insulator
What is a sensor? Thermometers Pressure sensors Acceleration sensors Light sensors Your multimeter You!
What happens if we want to communicate over a long distance? Let’s try that! What happens to the signal?
Analog or Digital Analog signals are like the signals that humans perceive. They can have any value. Digital signals are like the signals that computers use. (Remember Boolean logic?) They can only have discrete values.
Analog or Digital Analog signals are elegant, but susceptible to noise. Digital signals are simple, and not very susceptible to noise. Which one would be better for long distance communication?