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Examination Of Isolation Transformer

An isolation transformer is a transformer which generally has symmetrical windings used to decouple two circuits. The primary and secondary windings are physically separate from each other. Hence, they are also called 'insulate' since they are insulated from each other. Without electrically connecting two circuits an isolation transformer can take power or an AC signal from one device to another. AC signals can pass through but the DC signals are blocked and cannot pass through one circuit to the other. Ground loops also cause interference. The isolation transformer blocks this. It is used in highly sensitive equipments such as computers and laboratory instruments. It is used for supplying power along with electrostatic shields.

The isolation transformer is very useful when it comes to safety purposes. It is used in electronic testing, troubleshooting and servicing. It acts as a 1:1 power transformer in safety measures. A neutral wire is always connected to the ground. The object that is grounded might be at a hazardous potential difference when compared to the device. These may be objects such as the electric lamp, the desk, the concrete floor etc. In such a case when an isolation transformer is used the risk of a shock is contained within the device, since the bonding is eliminated.

In isolation transformers care should be taken while designing the capacitive coupling between two windings. If there is excessive capacitance then it will also couple the AC current from the primary to the secondary. There will be a ground shield between the primary and the secondary. If there remains any capacitive coupling between the secondary and the ground then it makes the secondary to become more balanced around the ground potential.

Isolation transformers are useful in many ways. It can be used to step up or down current. The primary and secondary windings can be constructed in such a way that it can match voltage between a 120V load and a 208 V. Power quality can be improved by having higher frequency noise currents. This can be achieved by the isolation transformer having a Faraday shield. With the Faraday shield it also helps to lessen the cumulative leakage current of the isolator and the connected equipment to the level below 300 microamphs. They help in giving better impedance matching of a critical load to an electrical circuit. Where patients have to be taken care of, Hospital Grade Isolation transformers protect sensitive equipment. It handles power surges and noise reduction. Micro processor based electronic equipments need to have reliable current. Isolation transformers have the 'code-legal' method. This re-bonds the electric system safely ground to the neutral conductor on the transformer secondary. This stops neutral to ground voltage and noise.

Some isolation transformers have a Faraday shield that is placed between the primary and the secondary windings. This takes care of many of the problems. It also takes care of the noise. Some isolation transformers have two Faraday shields. This solves the problem of referencing its internal shields to the ground. The inter-capacitance between the windings is also reduced.

So, isolation transformers play an important part in the sensitive electric and electronic equipments. Power surges and noise reduction is taken care of. Hence, it is very essential to know about isolation transformers and use them when they are needed for our equipments.