In simple words the flyback converter isolates the input and output, This method of isolated power supply using in DC-DC converter and other SMPS circuits.
Most of the SMPS circuits work based on this fllyback mechanism. The control circuit controls the high frequency signal to buck or boot the output voltage. In a linear power supply a lot of energy gets wasted like heat energy. The flyback converter circuit consists of a ferrite transformer, which is very small in size when compared with the other iron core transformer. The high frequency operation needs a ferrite core transformer and low number of copper windings.
This converter uses a transformer and high speed switching signal to change the frequency of the input voltage to several kilo hertz like 30-100KHz. This application is used in modern TV, LED drivers, Mobile chargers and many more electronics and home appliances.The major advantage of these circuits is that multiple output voltage can be taken from this single output transformer with proper galvanic isolation.
The main component of the flyback circuit is the ferrite core transformer. I already talked about the difference between ferrite core and iron core transformer, but the working and working principles are the same. When the circuit is ON, state charge flows through the coil and energy stores in the magnetic field. When the circuit is turned OFF the stored charge is transferred to the secondary winding of the transformer. This mechanism of energy transfer is used for multiple voltages at a time in the output section.
The control circuit is producing PWM signals which are driven by the MOSFETS or IGBTS. The duty cycle determines the output voltage. Many modern flyback converters have feedback mechanisms to stabilize the voltage under varying load conditions. This will also prevent the overvoltage or overcurrent situations.
