What Is so special about a flyback transformer?
The simple answer is how energy is stored in the gap of its core. Basically, it is a coupled inductor with a gapped core. During every cycle, the input voltage is applied to its primary winding. Energy is stored in the core's gap. It is then released to the secondary, which powers to the load.
How Does A Flyback Transformer Work in a Circuit?
As previously stated, flyback transformers have a gapped core, which stores energy without saturating the core. This energy storage capability is its differentiating factor. It is used in a flyback controller.
Using a MOSFET as a switch, the flyback controller will open and close a MOSFET switch with a duty cycle needed to attain the target output voltage. Refer to the figure on the right. Wihen the switch is closed, current flows through the transformer's primary winding, building up a magnetic field to store energy. The winding's polarity causes the diode connected to the secondary winding (output) to be reverse biased. In this state, energy is not released to the secondary winding or the load. When the MOSFET switch is opened, the magnetic field built up around the primary collapses, thereby transferring the stored energy to the secondary winding, the diode conducts, and the energy flows to the load.
What Kind of Devices use a Flyback Transformer?
Flyback transformers are commonly used in flyback converters for voltage transformation (often, step up) and circuit isolation. But they are used in other devices such as LED lighting, battery chargers, and more.
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