basic electrical engineering - t u - 2 - basic laws u2.pdf · asst. prof. dr. prapun suksompong...
TRANSCRIPT
Asst. Prof. Dr. Prapun [email protected]
2. Basic Laws
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Basic Electrical EngineeringECS 203
Office Hours: BKD, 4th floor of Sirindhralai building
Monday 14:00-16:00Thursday 10:30-11:30Friday 14:00-15:00
Measuring Resistance
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Measuring Resistance
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Analogy
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Voltage is like water pressure, current (amps) is like the flow rate, and resistance (ohms) is like the size of the pipe.
Increasing the voltage results in a greater current (more amps)—assuming a constant resistance-since increasing the pressure logically increases flow
Ohm’s Law: When V is increased
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Let’s change the load (resistor) to something else
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Ohm’s Law: When V is increased
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Starting with 1V
@ 9V: What’s the mount of current?
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Potentiometer (Pot)
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Pot as a variable resistor
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Manually adjustable resistor
Three terminals
The resistance between the middle terminal and either of the two sides depends on the position of the wiper.
Potentiometer (Pot)
11 [http://educationforengineer.blogspot.com/2013/05/potentiometer-working.html]
resistive strip
Pot as a variable resistor
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Manually adjustable resistor
Three terminals
The resistance between the middle terminal and either of the two sides depends on the position of the wiper.
p = iv and v = iR
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Overheating Resistor
14 [https://www.youtube.com/watch?v=0EmRY6s0UPk]47 resistor under 4W
Overheating Resistor
15 [https://www.youtube.com/watch?v=ZHv6VkKBPGA]
How to pronounce Kirchhoff?
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KCL
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Elements in one loop: KVL
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Voltage sources in series
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Voltage sources in series
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Voltage sources in series
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Voltage sources in series
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AAAA battery (usually read as quadruple-A)
(almost… they are 3.5 mm shorter)
Inception?
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Wow!Batteries within a battery
AAAA battery
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Surface Pen
Voltage sources in series
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Voltage sources in series
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Voltage sources in series
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12V “Car Alarm Remote” Battery
Voltage sources in series
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