Sources are the basic elements which provide energy to the circuit.
There are two types of sources.
A. Independent sources.
B. Dependent sources.
A. Independent sources:
Output value of an independent sources does not depend on any network variable such as current or voltage. The characteristics of independent source maybe time varying. There are two types of independent sources.
1. Independent voltage source.
2. Independent current source.
1. Independent voltage source : An independent voltage source is a two terminal element such as battery or a generator that maintains specified voltage between its terminals regardless of the rest of the circuit which the source is used. The value of this voltage is at any instant is independent of the value or direction of the current that flows through it. The terminal voltage may be constant or it may be some specified function of time.
2. Independent current source : An independent current source is a two terminal element through which a specified current flows or which produces specified current. The value and direction of this current at any instant is independent of the value or direction of the voltage that appears across the terminals of the source. The output current may be constant or it maybe a function of time.
B. Dependent sources:
If the value of voltage or current depends upon some other voltage or current then it is called as dependent source or controlled source. There are four types of dependent sources depending upon whether the control variable is voltage or current and whether the control source is voltage or current.
1. Voltage controlled voltage source (VCVS)
2. Voltage controlled current source (VCCS)
3. Current controlled voltage source (CCVS)
4. Current controlled current source (CCCS)
1.Voltage controlled voltage source (VCVS) :