Transformer energy storage time

Do Transformers store energy?

Separate primary and secondary windings facili-tate high voltage input/output isolation, especially important for safety in off-line applications. Ideally, a transformer stores no energy–all energy is transferred instantaneously from input to output. In practice, all transformers do store some undesired energy:

What is the maximum internal temperature a transformer can handle?

In consumer or industrial applications, a trans-former temperature rise of 40-50°C may be accept-able, resulting in a maximum internal temperature of 100°C. However, it may be wiser to use the next size larger core to obtain reduced temperature rise and reduced losses for better power supply efficiency.

Why is a transformer important?

In doing so, the transformer also provides important additional capabilities: The primary to secondary turns ratio can be es-tablished to efficiently accommodate widely dif-ferent input/output voltage levels. Multiple secondaries with different numbers of turns can be used to achieve multiple outputs at different voltage levels.

How do transformer losses affect power supply efficiency?

Transformer loss is sometimes limited directly by the need to achieve a required overall power supply efficiency. More often, transformer losses are limited by a maximum “hot spot” temperature rise at the core surface inside the center of the windings. Tempera-ture rise (°C) equals thermal resistance (°C/Watt) times power loss (Watts).

What happens when a transformer turns off?

When the switch turns off, the transformer magnetizing current causes the voltage to backswing, usually into a clamp. The reverse voltage causes the magnetizing current to decrease back to zero, from whence it started. The reverse volt-seconds will ex-actly equal the volt-seconds when the switch was ON.

What is a power transformer in switch-mode power supplies?

The purpose of a power transformer in Switch-Mode Power Supplies is to transfer power efficiently and instantaneously from an external electrical source to an external load. In doing so, the transformer also provides important additional capabilities: