Unit 6Series Circuits

Unit 6 Series Circuits

Objectives:

• Discuss the properties of series circuits.• List three rules for solving electrical values

of series circuits.• Compute values of voltage, current,

resistance, and power for series circuits.• Compute the values of voltage drop in a

series circuit using the voltage divider formula.

Unit 6 Series Circuits

A series circuit has only one path for current flow.

Unit 6 Series CircuitsFuses and circuit breakers are connected in series. All the circuit current must flow through the fuse. When the fuse opens, the circuit is disconnected from the power source.

Generator

Fuse

Unit 6 Series Circuits In a series circuit, the sum of all the voltage drops across all the resistors must equal the source voltage.

Unit 6 Series Circuits The series circuit shows four resistors having different voltage drops. Again, the sum of the voltage drops equals the applied source voltage in a series circuit.

Unit 6 Series Circuits

Rules for Calculating Series Circuit Values

1. The current is the same at any point in the circuit.2. The total resistance is the sum of the individual

resistors.3. The applied voltage is equal to the sum of the

voltage drops across all the resistors.

Unit 6 Series Circuits

Formulas for Calculating Series Circuit Values:

ITOTAL = I1 = I2 = I3 ……= INUMBER OF RESISTORS

RTOTAL = R1 + R2 + R3 ..…+ RNUMBER OF RESISTORS

ETOTAL = E1 + E2 + E3 …..+ ENUMBER OF RESISTORS

Unit 6 Series Circuits

Example of Series Circuit Values

ITOTAL = I1 = I2 = I3 = 2 A

RTOTAL = 20 Ω + 10 Ω + 30 Ω = 60 Ω

ETOTAL = 40 V + 20 V + 60 V = 120 V

Please insert figure 6-6

Unit 6 Series Circuits Power in a Series Circuit

The total power used in a circuit is equal to the sum of the power used by all parts.

PTOTAL = P1 + P2 + P3 …… PNUMBER OF RESISTORS

Please insert Figure 6-21

Unit 6 Series Circuits

The voltage divider circuits are used to provide different voltages between specific points.

Unit 6 Series Circuits

Review:

1. Series circuits have only one path for current flow.

2. The individual voltage drops in a series circuit can be added to equal the applied voltage.

3. The current is the same at any point in a series circuit.

Unit 6 Series Circuits

Review:

4. The individual resistors can be added to equal the total resistance of the circuit.

5. Fuses and circuit breakers are connected in series with the devices they are intended to protect.

Unit 6 Series Circuits

Review:

6. The total power in any circuit is equal to the sum of the power dissipated by all parts of the circuit.

7. When the source voltage and total resistance are known, the voltage drop across each element can be computed using the general voltage divider formula.