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Grob Basic ElectronicsGrob Basic Electronics

Chapter 4SERIES CIRCUITS

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Characteristics of a Characteristics of a Series CircuitSeries Circuit

Current is the same Current is the same everywhere in the circuit.everywhere in the circuit. The The total resistance total resistance is equal to theis equal to the sum sum of the of the

individual resistances.individual resistances. The The total voltage total voltage is equal to the is equal to the sumsum of the IR of the IR

voltage drops across the individual resistances.voltage drops across the individual resistances. Total power Total power is equal to the is equal to the sumsum of the power of the power

dissipated by each resistance.dissipated by each resistance.

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Current FormulasCurrent FormulasSeries CircuitsSeries Circuits

Total current is equal to each of the individual currents in the Total current is equal to each of the individual currents in the series string:series string:

Total current is equal to total voltage divided by total resistance:

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Resistance FormulasResistance FormulasSeries CircuitsSeries Circuits

Total resistance is equal to the sum of the individual resistances in the series string:

Total resistance is equal to total voltage divided by the circuit current:

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Voltage FormulasVoltage FormulasSeries CircuitsSeries Circuits

Total voltage is equal to the sum of the Total voltage is equal to the sum of the individual voltages in the series string:individual voltages in the series string:

Total voltage is equal to total current times Total voltage is equal to total current times total resistance:total resistance:

or

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Polarity of Resistor Polarity of Resistor IR Voltage DropsIR Voltage Drops

Negative at the end where the electron flow enters the resistance.

Positive at the end where the electron flow leaves the resistance.

When current flows through a resistance, a voltage equal to IR is dropped across the resistor. The polarity of this IR voltage drop is:

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Total power is equal to the sum of the power dissipated by the individual resistances in the series string:

Total power is equal to total voltage times circuit current:

Total PowerTotal PowerSeries CircuitsSeries Circuits

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Aiding and Opposing VoltagesAiding and Opposing VoltagesSeries CircuitsSeries Circuits

Series-aiding voltages are added. Series-opposing voltages are subtracted.

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Open CircuitOpen CircuitSeries CircuitSeries Circuit

When a series circuit is open, no current flows through any part.

When a series circuit is open, the applied voltage appears across the open portion.

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Logic FunctionsLogic FunctionsSeries CircuitSeries Circuit

Switches connected in series correspond to an AND gate function.

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End of Chapter 4End of Chapter 4