ElectronicsDan Simon

Cleveland State UniversityESC 120

Revised August 28, 2010

Voltage• Voltage is the amount of work needed to

move an electric charge• High voltage in an electrical system is like high

pressure in a hydraulic system • Common outlets in the United States:

120 Volts, 60 Hertz, alternating current (AC)

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Current• Electric current: The flow of electric charge

(electrons), measured in Amperes• One amp of current means a flow of one

Coulomb (6.241 × 1018 electrons) per second Amps = Coulombs / second

• High current in an electrical system is like high rate of flow in a hydraulic system

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Power

• Power: The rate at which current flows, measured in Watts

• Power is the product of voltage and current Watts = Volts × Amps

• Typical power consumption Air conditioner: 2000 W Clock: 2 W Television: 200 W Light bulb: 100 W

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Ohio’s average electricity cost:12 cents per kW-hr

ResistorsA resistor reduces the rate of flow of electric current, measured in Ohms: V = IRExample: If R1 > R2, then the current through R1 will be less than the current through R2

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Resistor Combinations

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Series: R = R1 + R2

Parallel: R = 1 / (1/R1 + 1/R2)

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Potentiometer

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Trimpot Adjuster

Capacitors

Capacitors store electrical energy

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TransistorsTransistors can be used as electrically-controlled switches. The current through the transistor is proportional to the voltage applied to the base.

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DiodesDiodes allow current to flow only in one direction.Light-emitting diodes (LEDs) emit light.The long lead connects to the positive voltage.

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Current flow

Solderless Breadboard

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Breadboard

Internal connections in orange

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Wire and Wire Strippers

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Multimeter

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Measures voltage, current, and resistance.

If you get unpredictable readings, check the battery!

Power Supply

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Regulated 5 Volt power supply: “wall wart”

You need to cut off the connector so that you can connect the bare wires to your breadboard

Breadboard

Breadboard with connector posts, ready for power supply connections

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LED Experiment

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Resistor value should be at least 400 ohms

Potentiometer Experiment

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Motor Experiment

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Motor Experiment

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