I wrote about the idea of representing AC circuits using complex numbers. Consider an RLC series circuit as shown in Figure 1. Now, the instantaneous value of the current flowing through this circuit is $$i(t)=I_m\sin(\omega t-\theta)\hspace{185pt}(1)$$ The instantaneous value of voltage is $$e(t)=Ri(t)+L\frac{di(t)}{dt}+\frac{1}{C}\int i(t)dt\hspace{130pt}(2)$$ $$=RI_m\sin(\omega t-\theta)+L\frac{d}{dt}\{I_m\sin(\omega t-\theta)\}+\frac{1}{C}\int I_m\sin(\omega t-\theta)dt\hspace{15pt}(3)$$ Here, there are two options: to …
Category: electrical engineering
Solution of RL series circuit using Laplace transform (for DC power supply)
Considering the RL series circuit shown in Figure 1, and assuming that the DC power supply is E and the current that flows through the circuit after t seconds is I, the following formula holds true. $$E=RI+L\frac{dI}{dt}\hspace{50pt}(1)$$ Let’s consider how to solve a differential equation using the Laplace transform to find the current I. Laplace …
Solution of RL series circuit using Laplace transform (for AC power supply)
fig.1 RL series circuit(Alternating current) Now, let’s consider an RL series circuit as shown in Figure 1, assume the AC power source is E, and think about how to find the current I that flows t seconds after turning on the switch. Now, in the circuit of Figure 1, the following circuit equation holds true …