TESTING OF HALF WAVE, FULL WAVE AND BRIDGE RECTIFIERS WITH
AND WITHOUT CAPACITOR
Aim: To determine the ripple factor, efficiency and regulation of the half wave, full wave
and bridge rectifier circuits with and without capacitor.
Apparatus: Diode-1N4007, load resistor -1kΩ & 1/2W, capacitor 100µF, transformer 15V-0-15V, ammeter 0-25mA (MI) and 0-25mA (MC), voltmeter 0-25V.
Theory:
Rectification is the process of converting the alternating quantity (AC) to the
unidirectional quantity (DC with pulsation). The transformer is used to step down the
voltage from 230V to the desired level. Then, the diode is responsible for the conversion
of ac available at the secondary of the transformer into DC with pulsation. Hence, the
diode used for this application is also referred as rectifier. The capacitor connected across
the load (resistor) is behaving as a filter. Filter is responsible to smooth the pulsating DC
into pure DC.
Half wave rectifier is one which converts the ac into pulsating dc during one half of the
cycle. It has poor ripple factor, conversion efficiency and voltage regulation.
Full wave rectifier is one which converts the ac into pulsating dc during both cycles. For
this process two diodes and centre tapped transformer are required. It has better ripple
factor, conversion efficiency and voltage regulation compare to the half wave rectifier.
The centre tapped transformer is costly compare to without centre tap. This can be
overcome by using 4 diodes in a bridge. The bridge rectifier has same ripple factor and
conversion efficiency as that of full wave rectifier, but better utilization factor.
By: Mr.L.Kumaraswamy M.E. (IISc),
Associate Professor, MCE, HASSAN
1
Procedure:
Without Capacitor:
1. Connections are made as shown in the figure for half wave rectifier circuit.
2. Measure the voltage across the terminals when the resistor is open circuited (No
load).
3. Connect the load resistor across the output terminals and note, the voltmeter
reading and ammeter readings (Irms and IDC).
4. Repeat the above procedure for full wave rectifier and bridge rectifier.
With Capacitor:
1. Connections are made as shown in the figure for half wave rectifier circuit with
capacitor.
2. Measure the voltage across the terminals when the resistor is open circuited (No
load) but capacitor is connected.
3. Connect the load resistor across the output terminals and note, the voltmeter
reading and ammeter readings (Irms and IDC).
4. Repeat the above procedure for full wave rectifier and bridge rectifier with
capacitor.
By: Mr.L.Kumaraswamy M.E. (IISc),
Associate Professor, MCE, HASSAN
2
CIRCUIT-Half Wave Rectifier
Fig.1
CIRCUIT-Half Wave Rectifier with capacitor
Fig.2
CIRCUIT-Full Wave Rectifier
By: Mr.L.Kumaraswamy M.E. (IISc),
Associate Professor, MCE, HASSAN
3
Fig. 3
CIRCUIT-Full Wave Rectifier with filtor
Fig .4
CIRCUIT-Bridge Rectifier
Fig.5
CIRCUIT-Bridge Rectifier with capacito
Fig.6
By: Mr.L.Kumaraswamy M.E. (IISc),
Associate Professor, MCE, HASSAN
4
Tabulation:
Position of
the switch
Open
IDC
IRMS
VM
VDC
Closed
Calculations:
Without Capacitor:
γ = [(IRMS/IDC)2-1]2
%η = (PDC/PAC)x100
PDC=IDC2RL
PAC=IRMS2RL
PDC=IDC2RL
PAC=IRMS2RL
%VR = (VNL-VL/VL)x100
With capacitors:
γ = 1/(2(3)1/2RLfC)
%η = (PDC/PAC)x100
%VR = IDC/2fC
By: Mr.L.Kumaraswamy M.E. (IISc),
Associate Professor, MCE, HASSAN
5