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Toroids and Toroidal Transformers

What do you need to know about inrush currents and toroidal transformers? It is essential to know about inrush currents because they pose risks if not adequately managed. For instance, an inrush current might cause circuit breakers to fuse and blow. In a worst-case scenario, it causes the transformer to fail. Lastly, inrush currents also limit the number of devices that can be connected to a single core’s power source.


Toroid transformers are necessary devices in everyday life because they help many major appliances and devices run.

Problems occur because an inrush current has adverse effects on the magnetic properties of the toroidal core. Inrush causes energy loss, so it is beneficial for engineers to work to reduce initial inrush currents. The easiest way to control inrush is with an inrush limiter.

Toroid Transformer

When a toroidal transformer is switched on, that initial source of power will send a surge of energy to the device (inrush current). To prevent damage to the power supply, limiters are integrated into product design.

Some advantages of using limiters for reducing inrush problems on toroids include:

  • They use standard fuses
  • They are compatible with lower rated rectifier bridges
  • Limiters allow engineers to use lower rated components
  • They reduce currents at startup, and they also reduce power sag noise that is commonly caused by under voltage or brownouts.

Protect your toroidal transformers with inrush current limiters.

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