What Are Current Sense Transformers?

Current sense transformers are a type of instrument transformer that are used to measure current values in a conductor, mainly used in high-current circuits. In such transformers, the primary has very few windings and is connected in series with the conductor carrying the current that is to be measured. This is why current sense transformers are also known as series transformers. The secondary, on the other hand, has many windings wound around a ferromagnetic core. These transformers are easy to implement, accurate, and reliable under even the harshest environmental and thermal conditions. An ideal current sense transformer has zero winding resistances, infinite inductance, perfect coupling and no parasitics.

Current sense transformers are also a type of step-up transformer, wherein the current in the primary produces a corresponding reduced current in the secondary, which can be measured using an ammeter. Also, the current in the primary can be calculated by knowing the turns ratio of the transformer. These transformers are exclusively designed to provide the highest level of safety to the operators by regulating and stepping down voltages to machine tool control devices.

Which applications are current sense transformers used in?

Current sense transformers are used extensively in high-power applications and power transmission lines, as they provide reliable current sensing with minimal insertion loss. They are also used to perform circuit control and measure current for power measurement and control. They are also used in safety protection and current limiting applications. Moreover, they are also used with small accurate instrumentation as they can drastically step down current levels. The common applications include watt meters, watt-hour meters, protective relays, and power factor meters.

Which are the two main types of current sense transformers?

Current sense transformers can be of two types – high-frequency and low-frequency transformers – that are specially designed for high and low frequency applications, with specially selected core materials that are tailored to specific frequency ranges. These devices can thus measure current for a range of different frequencies in various applications. Low frequency current sense transformers are ideal for operations between 50-60 Hz, and high frequency current sense transformers are designed to monitor current more than 250 Hz. You can also have specially designed current sense transformers that can operate over a frequency range of 20 to 200 kHz. Such transformers need to be specifically designed for usage in harsh environments, thus requiring UL-rated 130°C materials for production. With these different frequency ranges, almost all industrial applications are covered.

As a world-class transformer manufacturer in India, Miracle Electronics offers a wide range of the most reliable transformers. Dedicated to creative design and constant innovation, they are capable of providing solutions for even the most unusual current sensing requirements. You can also have all kinds of transformers customized as per your requirements. And, all these transformers, whether standard or customized, are RoHS and REACH compliant, and can also be available with CE and UL marks on request. So, keep it safe with Miracle Electronics’ transformers – a bundle of massive efficiency!