Page 170 - Electrician - TT (Volume 1)

ELECTRICIAN - CITS

RLC Circuit at resonance

• XL=XC
• Z=R
• Current is maximum
• Impedance is minimum

• Supply voltage and circuit current are in phase
• The series circuit is known as Accepter circuits.
RLC Parallel circuit- consist of resistance, inductance and capacitance connected in parallel
When resistance R in ohm , inductance L in Henry and capacitance C in Fared are connected in parallel to the
supply voltage is called a simple RLC parallel circuit.
• Supply voltage across all the component are same(VS)
• IR is current through the resistance which is in phase with VS
• IL is current through the inductor lags behind voltage VS
• IC is the current through capacitor leads the voltage VS

• In RLC parallel circuit, the supply voltage ‘Vs’ is same across all 3 components .Therefore Vs is taken as
reference
V
I
R
R
V V
I
L
X L 2 fL
V
I V.2 fL
C
X C
Therefore, I vector sun of (I I I )
T P L C
I I 2 R (I L I C )
T
2
I (I L I C ) 2
R
I I 2 R (I L I C ) 2
T

I V 2 V V 2 V where I : R V I , L X V I , C X V

E
R X L X c Z L C

157
CITS : Power - Electrician & Wireman - Lesson 26-29