Converting a voltage into a current source makes the circuit simpler and the circuit solution are simplified especially with the mixed sources. The process is known as source conversion and it is an application of Thevenin’s theorem and Norton’s theorem.
Any combination of battery and resistance with two terminal can be replaced by single voltage source and single series resistor. The value of the voltage source is an open circuit voltage at the terminal, and the values of series resistor is voltage source divided by the current with the terminals short circuited.
The linear network behind a pair of output terminal can be replaced with a constant current source in parallel with an internal resistance.
When a voltage source is converted into the current source or vice versa using ohm’s law method is known as source conversion.
Current source to voltage source conversion:
A current source which is connected in parallel to a resistance across two terminals gives
V =IR, where, V= value of voltage source which is connected across the same two terminal in series with the same resistance, R = resistance and I = value of current source.
Voltage source to current source conversion:
A voltage source which is connected in series with a resistance across two terminals gives
I =V/R , where, I = value of current source which is connected across the same two terminal in parallel to the same resistance.
For source conversion the voltage source must be in series with a resistance and also the current source is required to connected in parallel to the resistance.
Source conversion can be done using ohm’s law to take an existing current source in parallel with a resistance, and replace it with a voltage source in a series with the same resistance.
Ohm’s law :
Ohm’s law states that voltage is directly proportional to current.
V = IR, where R is constant
Since, the source conversion can be derived from the other so, the source conversion are bilateral.
Source conversion is an application of Norton’s theorem to voltage source or Thevenin’s theorem to a current source. Application of both the theorem gives the quantities associated with the equivalence. Source conversion are used to exploit the equivalence of a real voltage source and a real current source , such as battery. Consider we have a real current source I, which is in parallel with an Impedance and current source is an ideal source . and the current source is rated as I ampere and the parallel resistance has an impedance Z, then by applying source conversion gives an equivalent real voltage source which is in series with impedance .the new voltage source V = I.Z
Figure 1. An example of a DC source transformation. Notice that the impedance Z is the same in both configurations.
QUESTION & ANSWER
1. What is a source conversion. Explain??
Source conversion is an application of Norton’s and Thevenin’s Theorem. It is a process to obtain a simplified circuit by converting the voltage source into current source and vice versa using ohm’s law.
2. Explain Thevenin’s theorem??
Any combination of battery and resistance of two terminal can be replaced by a single voltage source and a single series resistor. The value of the voltage source is open circuit voltage at the terminal, and the value of the series resistor is a voltage source divided by the current with the terminal short circuited.
3. How a current source is converted into a voltage source??
A current source which is connected in parallel to a resistance across two terminal gives
V = IR, where v is the value of voltage source that will be also connected to the same two terminal in series with the same resistance.
4. How the voltage source is converted to current source??
Voltage source which is connected in parallel to a resistance across two terminal gives
I = V/R , where the value of I is the current source value which is connected across same two terminal in parallel to the same resistance.