Here we are going to see how to build a Bridgeless Boost Rectifier, (i.e. Bridgeless Boost Converter). The basic boost converter circuit is shown below.
The above circuit shows the boost converter circuit from a DC voltage which is rectified from an AC voltage by means of a bridge rectifier. The boost voltage depends on switching the MOSFET (switching device) and the energy stored in the inductor.
Boost voltage depends on the switching frequency and duty cycle of the pulse.
Calculation of a Duty cycle:
D = (Ton/T) Where, Ton is turn on time of the Pulse. T is Ton + Toff total time. Calculation of a Frequency: F = (1/T) Where,
T is total time in sec.
Bridgeless Boost Rectifier:
Here comes a proposed boost converter as Bridgeless Boost Rectifier. The circuit is shown below.
In Bridgeless Boost Rectifier the alternating current is converted to Boost DC voltage without bridge rectifier in the circuit. This is done with the help of a Zero Crossing Detection (ZCD). With reference to the positive and negative sine wave the PWM is generated for the switching devices in the circuit.
The above figure explains the comparison of ZCD and Reference sine wave.
Bridgeless Boost Rectifier`s detailed explanation and working is shown in the following link