In the context of electrical engineering and electronics, "A.C. fundamentals" generally refers to the fundamental concepts and principles related to alternating current (A.C.) circuits. One important concept in A.C. circuits is the pulse response.
Pulse Response:
The pulse response of an A.C. circuit refers to the behavior of the circuit when subjected to a sudden change in voltage or current. In other words, it describes how the circuit reacts when an abrupt input signal, often in the form of a pulse or step function, is applied to it. This concept is particularly relevant in the analysis of circuits that include reactive components like capacitors and inductors.
Capacitor Response:
When a sudden voltage change is applied to a capacitor in an A.C. circuit, the capacitor reacts by charging or discharging. In the case of a sudden increase in voltage (positive step), the capacitor charges, and its voltage gradually rises over time according to the equation:
(
)
=
final
×
(
1
−
−
/
)
V(t)=V
final
×(1−e
−t/τ
)
Where:
(
)
V(t) is the voltage across the capacitor at time
t
final
V
final
is the final voltage to which the capacitor charges
t is time
=
×
τ=R×C is the time constant of the circuit (product of resistance
R and capacitance
C)
Inductor Response:
When a sudden current change is applied to an inductor in an A.C. circuit, the inductor reacts by inducing a voltage across itself to resist the change in current. In the case of a sudden increase in current (positive step), the inductor induces a voltage opposing the change. The relationship between the induced voltage and time is given by:
(
)
=
−
×
V(t)=−L×
dt
di
Where:
(
)
V(t) is the induced voltage across the inductor at time
t
L is the inductance of the inductor
dt
di
is the rate of change of current with respect to time
These pulse responses are important for understanding how A.C. circuits behave when subjected to sudden changes in input signals. They are often used in the analysis and design of circuits involving capacitors, inductors, and other reactive components.
It's important to note that the above descriptions assume ideal components and do not take into account factors such as resistance in the wires, non-ideal behavior of components, and other real-world considerations.