Calculate Output Voltage - Half Wave Rectifier

The input to a rectifier is typically a sinusoidal AC voltage defined as . If you are given the RMS value of the AC input (e.g.,

Vdc=12π∫0πVmsin(θ)dθ=Vm2π[−cos(θ)]0π=Vmπcap V sub d c end-sub equals the fraction with numerator 1 and denominator 2 pi end-fraction integral from 0 to pi of cap V sub m sine open paren theta close paren space d theta equals the fraction with numerator cap V sub m and denominator 2 pi end-fraction open bracket negative cosine open paren theta close paren close bracket sub 0 raised to the pi power equals the fraction with numerator cap V sub m and denominator pi end-fraction 3. Account for Diode Forward Bias Real diodes have a forward voltage drop ( Vdcap V sub d ), typically for silicon. This reduces the peak output: calculate output voltage half wave rectifier

The output voltage for a half-wave rectifier is defined by the average value and the effective value Vmcap V sub m is the peak input voltage. The input to a rectifier is typically a

Vpeak(out)=Vm−Vdcap V sub p e a k open paren o u t close paren end-sub equals cap V sub m minus cap V sub d The adjusted DC formula becomes: This reduces the peak output: The output voltage

In a half-wave rectifier, the diode only conducts during the positive half-cycle. The average value is the integral of the sine wave over one full period ( ), divided by that period:

Vrms=12π∫0π(Vmsin(θ))2dθ=Vm2cap V sub r m s end-sub equals the square root of the fraction with numerator 1 and denominator 2 pi end-fraction integral from 0 to pi of open paren cap V sub m sine open paren theta close paren close paren squared space d theta end-root equals the fraction with numerator cap V sub m and denominator 2 end-fraction Final Result

Vdc≈Vm−Vdπcap V sub d c end-sub is approximately equal to the fraction with numerator cap V sub m minus cap V sub d and denominator pi end-fraction 4. Calculate RMS Output Voltage