Lesson-9-PARALLEL-CIRCUIT..hivcghdf.pptx

Parallel Circuit

1. PARALLEL CIRCUIT

2. Parallel circuit has its unique characteristics which are widely used than any other type of circuit specially in house/building wirings. The distribution of power in large cities is accomplished by maze of feeder lines which are all connected in parallel. A parallel circuit has more than one path of current to move.

3. VOLTAGE in Parallel Electrical load is placed directly across the main electrical supply or source and this causes each load to operate at the same voltage independently. An electrical component should never be connected in parallel circuit if it has lower voltage rating than the source.

4. Equation in Voltage E t = E 1 = E 2 = E 3 = E 4 =…. Where: E t Total Voltage E 1 Voltage Across component 1 E 2 Voltage Across component 2 E 3 Voltage Across component 3

5. CURRENT in Parallel The component in the parallel circuit operates independently to one another. Each component will take current in accordance with its resistance. The number of separate paths is equal to the number of components in parallel. The total current in the parallel circuit is equal to the sum of the current of individual components.

6. Equation in Current I t = I 1 + I 2 + I 3 + I 4 +…. Where: I t Total Current I 1 Current flowing in component 1 I 2 Current flowing in component 2 I 3 Current flowing in component 3

7. RESISTANCE in Parallel Total Resistance (R t ) is always be less than the smallest value of resistance (R) in the circuit when two or more resistors are present. Adding more parallel branches to the circuit will increase the total current. The total circuit resistance decreases as current increases in parallel circuit.

8. EQUAL RESISTANCE IN THE CIRCUIT Parallel circuit where the resistance of the component is same.

9. UNEQUAL RESISTANCE IN THE CIRCUIT Reciprocal formula 1 = 1 + 1 + 1 + … R t R 1 R 2 R 3 Where: R t = Total resistance R 1 = Resistance of component 1 R 2 = Resistance of component 2 R 3 = Resistance of component 3

10. Example: Find the total resistance in the circuit

11. alternative solution R t = ______1_________ 1/R 1 + 1/R 2 + 1/R 3 R t = ______1_________ 1/3 + 1/6 + 1/8 R t = ________1_________ 0.333+ 0.167 + 0.125 R t = ___1____ 0.625 R t = 1.6 Ω Same as previous answer but different equation

12. Example: A 3 ohm resistor and 6 ohm resistor is connected in parallel. Compute the combined resistance

13. Example: Find the total current in the given circuit.