ME 361: Instrumentation and Measurement

Electronics : Basics

Kazi Arafat RahmanLecturerDept. of Mechanical Engineering, BUET

Teacher.buet.ac.bd/karahman

Voltage Divider…..

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Voltage Divider…..example

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KVL…..

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KCL…..

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Diodes…..

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Diode…..

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Diode: home work 1….

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Zener Diode…..

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Diode: some important factors…

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• Forward voltages of silicon diodes are really small ( ̴0.6-0.7 volts)

• Diodes don’t have resistance. If the voltage is below a diode’s forward voltage, then the element looks like an open circuit. If the voltage is below the forward voltage, the element behaves as a short circuit

Diode: some important factors…

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• Forward voltages of silicon diodes are really small ( ̴0.6-0.7 volts)

• Diodes don’t have resistance. If the voltage is below a diode’s forward voltage, then the element looks like an open circuit. If the voltage is below the forward voltage, the element behaves as a short circuit

Diode: home work 2…..

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Inductor…..

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• The rate of current change in an inductor depends on the voltage applied across it, whereas the rate of voltage change in a capacitor depends on the current through it. The defining equation for an inductor is,

• The direction (polarity) of the voltage will be in the direction that opposes the change in current • An inductor “likes” to pass current when the voltage across its leads does not change (e.g., dc signals) but “hates” to pass current when the voltage across its leads is changing with time (e.g., high-frequency ac signals)

Inductive loads and diode protection…

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• What happens if you open a switch that is providing current to an inductor?

Relays…

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Relays…

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