Parallel DC Circuit

Parallel DC Circuit

Parallel DC circuit include as many parallel lines as desired.

1. In a parallel circuit, voltage is the same throughout each parallel leg, no matter how many legs are added.

Vs = V1 = V2 = V3

2. Current through a parallel circuit is the sum of the current in each leg.

IT = I1 + I2 + I3

3. Resistance total calculation as follows:

RT = 1 / ( 1/R1 + 1/R2 + 1/R3 )

Example : Parallel DC circuit Analysis :

Current Divider

The current divider is mostly used to determine the current on a parallel resistor circuit with only two brances.

Example :

Formula :

IRX = IT ( RT / RX )

Series DC Circuit

Series DC Circuit

All components of the series circuit are on one line from the power supply and return.

1. The voltage total is equal to the sum of the series voltage drops in the circuit :

Vs = VR1 + VR2 = VR3

2. The same current must flow through all component.

IT = IR1 = IR2 = IR3

3. The resistance total in a series circuit is the sum of the resistance in the circuit.

RT = R1 + R2 + R3....

Example : Series DC Circuit Analysis:

Voltage Divider

1. A voltage divider is used in a circuit where the resistor are connected in a series.

2. The value of the drop voltage can be easily calculated using the voltage divider formula without knowing the

    current.

3. Example :

Quantities And Units (part-2)

c) Voltage (V)

1. Voltage is the potential energy that causes the current to flow in a circuit.

2. This potential energy is produced from a battery or a generator- electromotive fore (emf)

3. The current flows from a higher pressure ( + ) to a lower pressure point ( - ).

4. The unit for the potential difference and emf is volt (V).

5. Formula:

V = I X R

d) Resistance (R)

1. Resistance is a quantity that limit the flow of a current in a circuit.

2. The important characteristic is characteristic is  : low resistance in a circuit allows high current flow, 

    however if the resistance is high the current flow in the circuit will reduced or will become zero.

3. A good conductor = a very low resistance and a good insulator = a very high resistance.

4 Formula

R = V/I

e) Power (P)

1. Power is the rate at which energy is used.

2. A watt is unit for power.

3. Formula :

P = W/T

f) Energy (E)

1. Energy is the capability to do work in a tome.

2. Energy is measured in joule. One joule is equivalent to one watt in one second.

3. Formula :

W = V X I

Direct Current Circuit-(DC)

Direct Current (DC)

Direct Current (DC) is the flow of current in one direction. A basic DC circuit is illustrated as below

Quantities And Units (part-1)

a) Charge (C)

1. Electrical Charge is created when proton and electron charges are separated - it's static.

2. Proton are positively charged particles, while electron are negatively charged particles.

3. Electrical charge is measured in coulomb. One coulomb is the total charge of 6.25 X 10^18 electrons.

Formula :

Q = I X T

b) Current (I)

1. Current is the movement of charge from one point to another in a uni of time.

2. There are two ways of defining the flow of current; first, the conventional current flow and second, the    

    electron current flow. Refers to an illistrated as in figure below;

3. Formula :

I = V/R