This document describes an experiment to simulate a single-phase half-wave controlled rectifier circuit with both resistive and RL loads. The circuit uses a thyristor (SCR) to control the rectification of a 230V AC supply. For the resistive load, the output voltage was measured as 62.1V RMS and the output current was 0.48A. For the RL load, the inductance was calculated as 1.138H based on the circuit parameters. Waveforms of voltages and currents were plotted for both circuits to observe the output performance.

1. Date: 26/11/2020 EXPERIMENT NO. 4 VARUN CHOUDHARY
HALF WAVE CONTROLLED RECTIFIER B17056EE
AIM:
To design and simulate a single phase half wave controlled rectifier with following:
1. To feed a resistive load
2. To feed an RL load
And plot waveforms of voltages and currents.
COMPONENTS REQUIRED:
Thyristor S4X8ES1 1
Resistors 268.14Ω 1
1MΩ 1
Inductance 1.138H 1
AC Supply 230V 1
Pulse Generator 1
THEORY:
SCRs are very useful in ac circuits where they may serve as rectifiers whose output
current can be controlled by controlling the gate current. An example of this type of application
is the use of SCRs to operate and control dc motors or dc load from an ac supply.
Ratings of SCR:
Model: S4X8ES1
Vrated = 400V
Irated = 0.8A
IGT = 5µA

2. 100
OBSERVATIONS:
➢ To feed a resistor load:
Input voltage = 230V
Input frequency = 50Hz
Output Voltage, V= 10+S
×Vrated�����
S = 0+5+6+6 = 17
Vrated is input voltage 230V rms
Amplitude, Vm = 230 √2 = 325.27V
Output voltage = 62.1V
Output current = 0.6x0.8 = 0.48A
Vo(dc)=
325.27 (1 + cosα)
2π
= 62.1V
Cosα = 0.199575 ⇒α = 78.480
Ts = 1/50 = 20ms
TON =(78.48/360)x 20ms = 4.36ms
Vo(RMS)= 128.7 V
Output resistance R =
128.7
0.48 = 268.14 Ω

3. ● Input and OutputVoltage:
● Input and Outputcurrent:
●
●
● Voltage across SCR:
➢ To feed an RL Load

4. 360
Input voltage = 230V
Input frequency = 50Hz
Output voltage = 62.1V
Output resistance R = 268.14 Ω
β = π + α
62.1 = 325.27 (cosα− cos(π+α))
2π
325.27 (2cosα)
2π
cosα = 0.59978 ⇒α = 53.140
and β = 180 + 53.14 = 233.140
TON = 53.14
x 20ms = 2.95ms
sin(β − Φ) = sin(π + α − Φ) = − sin(α − Φ)
ω = 2 π f = 100 π
−Rπ
100πL
or Φ = α
for Φ = α , L = RtanΦ
ω
268.14 (tan53.14)
100π
L = 1.138H
=
-1 = e
=

5. ● Input and OutputVoltage:
● Input and Outputcurrent:
● Voltage across SCR:

6. ● Voltage across Inductor and Resistor:
RESULT:
A Single phase half wave controlled rectifier was designed and simulated to feed a resistor
load and an RL load using LTSpice.The different waveforms for voltages and currents in the
circuits were plotted.