Voltages in Half-Wave Rectifier

Calculate RMS voltage and average voltage of half-wave rectification

Calculate Half-Wave Rectification

Input Voltage

Enter either the RMS voltage or the peak voltage of the AC voltage. The diode forward voltage is automatically considered.

V
V
Results
Input Values
Input URMS:
Input UPeak:
Output Values
After Diode U₂:
Output Uavg:
Output URMS:

Voltage Diagram

Voltage Comparison
Circuit Type

Half-Wave Rectifier

  • Only positive half-waves pass through the diode
  • Simplest form of rectification
  • High ripple in output voltage
Half-wave rectifier circuit diagram

Circuit diagram: Half-wave rectifier

Theory of Half-Wave Rectifier

Operating Principle

The half-wave rectifier is the simplest type of rectification. The load resistor takes over the role of the series resistor here. Only the positive half-waves of the input voltage reach the load resistor, the negative ones are "cut off" by the diode. Such a voltage is also called pulsating DC voltage.

Characteristic Properties
  • High Ripple: Only every second half-wave is transmitted
  • Poor Transformer Utilization: Only 50% of available energy is used
  • Simple Construction: Can also be operated without a transformer
  • Low Cost: Only one diode required
Voltage Relationships
Output voltage after diode:
\[U_2 = U_S - U_D\]

Peak voltage minus diode forward voltage

DC component (average value):
\[U_G = \frac{U_2}{\pi}\]

About 31.8% of peak voltage

RMS value:
\[U_{RMS} = \frac{U_2}{2}\]

50% of peak voltage

Form factor:
\[F = \frac{U_{RMS}}{U_G} = \frac{\pi}{2} ≈ 1.57\]

Ratio of RMS to average value

Disadvantages
  • High ripple (100% with pure load)
  • Poor transformer utilization
  • High harmonic content
  • Low output voltage
Advantages
  • Simplest construction
  • Low cost
  • Few components
  • Can be operated without transformer
Typical Applications
  • Simple power supplies
  • Battery chargers
  • DC motors with low requirements
  • Measuring instruments
Input Voltage (AC Voltage)
Input voltage

Sinusoidal AC voltage at input

Output Voltage (rectified)
Output voltage

Pulsating DC voltage at output

Symbol Directory
UGDC component (average value) [V]
URMSRMS value of output voltage [V]
USInput peak voltage [V]
U₂Output peak voltage after diode [V]
UDDiode forward voltage (typ. 0.7V) [V]
πPi ≈ 3.14159


Other electronics functions

LED resistor  •  Zener diode resistor (variable)  •  Zener diode resistor (fix)  •  Half-Wave rectification  •  Half-Wave rectification with capacitor  •  Full-Wave rectification  •  Full-Wave rectification with capacitor  •