What is a flyback transformer used for?

Flyback transformers are used to provide voltage transformation and circuit isolation in flyback converters. Flyback transformers are the most popular choice for cost-effective, high-efficiency isolated power supply designs up to approximately 120 Watts.

Is a flyback transformer AC or DC?

The primary winding of the flyback transformer is driven by a switch from a DC supply (usually a transistor). When the switch is switched on, the primary inductance causes the current to build up in a ramp.

Why is it called a flyback?

The reason it is called a flyback transformer is because the primary winding uses a relatively low-voltage saw-tooth wave. The wave gets strengthened first and then gets switched off abruptly; this causes the beam to fly back from right to left on the display.

What is the output of a flyback transformer?

A flyback transformer, also known as a line output transformer, comprises coupled inductors, making it unique from a typical transformer. It generates voltage from a few kilovolts up to 50 kilovolts with high-frequency currents from 17 kHz to 50 kHz.

How do I know if my flyback transformer is bad?

Signs & Symptoms of a Bad Flyback Transformer

1. Picture Does Not Display. A sure sign of a bad flyback transformer is when a picture does not display on the monitor.
2. Monitor or Picture Blinks. A bad flyback transformer causes the monitor or picture to blink.
3. Television or Monitor Gets Hot.
4. Blown Fuses.

What is the input voltage of flyback transformer?

230 V
With an input of 230 V, these transformers can provide an output of around 20,000 V. They can even operate at voltages as low as 12 V to 5V.

Why do flyback transformers fail?

Flybacks fail in several ways: Overheating leading to cracks in the plastic and external arcing. If there is no major damage to the windings, repair may be possible. However, arcing from the windings punctures their very thin insulation so that shorted windings may already have developed.

How do I test a CRT flyback transformer?

How to check if a primary winding is good or bad in a Flyback Transformer? a) By using a flyback/LOPT tester, this instrument identifies faults in primary winding by doing a ‘ring’ test. b) It can test the winding even with only one shorted turned. c) This meter is handy and easy to use.

What is flyback transformer?

Flyback transformer. A flyback transformer (FBT), also called a line output transformer (LOPT), is a special type of electrical transformer. It was initially designed to generate high voltage sawtooth signals at a relatively high frequency. In modern applications, it is used extensively in switched-mode power supplies for both low (3 V)…

How does a flyback converter work?

During each cycle, when the input voltage is applied to the primary winding, energy is stored in the gap of the core. It is then transferred to the secondary winding to provide energy to the load. Flyback transformers are used to provide voltage transformation and circuit isolation in flyback converters.

What is the peak primary current of a flyback transformer?

When designing a flyback transformer, the worst-case condition of maximum load at the minimum input voltage creates the highest (peak) primary current requirement. Select a transformer that has a peak primary current (Ipk) or primary saturation current (Isat) that is well above the expected primary current peak for your application.

What is the voltage of a flyback circuit?

Other things to note are that these flybacks are sometimes stepped up on the circuit board with some sort of cascade or voltage multiplier, and therefore have a lower voltage secondary winding. Correspondingly, you should expect no more than around 10kV from them at most.