1 Grob Basic Electronics Chapter 4 SERIES CIRCUITS

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10 Characteristics of a Series Circuit l Current is the same everywhere in the circuit. l The total resistance is equal to the sum of the individual resistances. l The total voltage is equal to the sum of the IR voltage drops across the individual resistances. l Total power is equal to the sum of the power dissipated by each resistance. l Current is the same everywhere in the circuit. l The total resistance is equal to the sum of the individual resistances. l The total voltage is equal to the sum of the IR voltage drops across the individual resistances. l Total power is equal to the sum of the power dissipated by each resistance.

11 Current Formulas Series Circuits l Total current is equal to each of the individual currents in the series string: l Total current is equal to total voltage divided by total resistance: l Total current is equal to each of the individual currents in the series string: l Total current is equal to total voltage divided by total resistance:

12 Resistance Formulas Series Circuits l Total resistance is equal to the sum of the individual resistances in the series string: l Total resistance is equal to total voltage divided by the circuit current: l Total resistance is equal to the sum of the individual resistances in the series string: l Total resistance is equal to total voltage divided by the circuit current:

13 Voltage Formulas Series Circuits l Total voltage is equal to the sum of the individual voltages in the series string: l Total voltage is equal to total current times total resistance: l Total voltage is equal to the sum of the individual voltages in the series string: l Total voltage is equal to total current times total resistance: or

14 Polarity of Resistor IR Voltage Drops l Negative at the end where the electron flow enters the resistance. l Positive at the end where the electron flow leaves the resistance. l Negative at the end where the electron flow enters the resistance. l 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:

15 l Total power is equal to the sum of the power dissipated by the individual resistances in the series string: l Total power is equal to total voltage times circuit current: l Total power is equal to the sum of the power dissipated by the individual resistances in the series string: l Total power is equal to total voltage times circuit current: Total Power Series Circuits

16 Aiding and Opposing Voltages Series Circuits l Series-aiding voltages are added. l Series-opposing voltages are subtracted. l Series-aiding voltages are added. l Series-opposing voltages are subtracted.

17 Open Circuit Series Circuit l When a series circuit is open, no current flows through any part. l When a series circuit is open, the applied voltage appears across the open portion. l When a series circuit is open, no current flows through any part. l When a series circuit is open, the applied voltage appears across the open portion.

18 Logic Functions Series Circuit Switches connected in series correspond to an AND gate function.

19 End of Chapter 4