The role of isolation transformers is to transmit electrical power to a device from a power source. Technically, all transformers can be defined as an isolation transformer, due to the fact that all transformers use the process of induction to convert electricity, as opposed to the use of a conductor. However, the main characteristic that sets isolation transformers apart from other categories is that they are designed to isolate electricity, or isolate the device from the power source. Numerous applications utilize isolation transformers. These applications include uninterrupted power supplies (UPS), test and measurement systems, robotics, motor controls, light fixtures, medical electronics, industrial control panels, data communications, avionics, and audio systems.
A complex series of different types of transformers are used to safely and efficiently transmit electricity from power plants to the power outlets different buildings. While high-voltage transformers are used to lower the voltage to a level suitable for homes and businesses, and power transformers assist in the distribution of electricity for use in electronic devices, isolation transformers are not used to alter the voltage level. They rather separate two conductive elements within a transmission system, and allow for controlled electrical transmission all while eliminating unwanted electrical discharge in the process. In everyday handheld consumer devices such as electric shavers and hair dryers, isolation transformers are necessary for these devices to run safely.
Since their invention, isolation transformers have played a pivotal role in increasing the safety of numerous electronic devices. Isolation transformers are able to prevent unwanted electrical discharge. Unwanted discharge can be dangerous, especially in devices such as electric shavers and hair dryers which are commonly used near sinks. Fortunately, the use of isolation transformers greatly minimizes this risk. The medical industry uses isolation transformers extensively in their equipment, as medical equipment is highly sensitive, and even the slightest bit of interference could pose a significant risk for the well-being of patients and medical employees. Isolation transformers are utilized to carefully regulate the amount of electricity that is used to power devices such as patient monitoring equipment, hospital beds, medical lab equipment, dental chairs, and electric powered dental tools.
Furthermore, isolation transformers can substitute for an isolated ground circuit, and they are capable of eliminating noise. Standalone isolation transformers have the ability to remove common mode noise. As stated before, an isolation transformer does not change the voltage. Instead, they have the ability to “shield” a device from electromagnetic noise that could be generated by stepping voltage or the fluctuation of electric current. Unwanted discharge is regulated by way of a process known as galvanic isolation. Galvanic isolation is the electrical and physical isolation from an input power circuit. Galvanic isolation does not prevent an electrically transmissive system from carrying out its usual functions. Rather, it still allows for the transfer of electrically charged particles using means such as induction. Examples of applications whose transformers utilize galvanic isolation in its electric transmissions include personal computers. International safety agencies require every personal computer to have galvanic isolation between the input power source and the structure of the computer itself in order to prevent electric shock. The installation of an isolation transformer within a computer can greatly reduce the computer’s intake of common mode noise. A disadvantage of an isolation transformer, however, is that it can generate extra heat which may shorten the computer’s battery life if the transformer is close to where the batteries are located.
One configuration that an isolation transformer can be found in is toroidal, or donut-shaped. Toroid transformers have several advantages, including its light weight and compact size, which allow for it to be included in numerous applications. The windings of a toroidal transformer run through the center of its core, and is thus evenly distributed throughout the device. The core can be constructed from silicon iron or nickel-iron alloy. Amorphous alloys and powdered iron are a wiser choice of core material for higher frequency applications. Furthermore, toroidal transformers have the ability to minimize stray field radiation and audible noise. To further reduce stray magnetic fields, toroidal isolation transformers can be equipped with a metal band. For devices such as patient monitoring machines that leave little allowance for interference, additional insulation may be added to an isolation transformer. There are many other configurations of isolation transformers that are available. Thus, it is recommended that you consult a transformer manufacturer. Some manufacturers offer a variety of both standard and custom designed isolation transformers to ensure all of their customer’s needs are met, and that the desired pieces of equipment can run efficiently and safely.
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Three Phase Isolation Transformer – Johnson Electric Coil Company
Small Isolation Transformers – Johnson Electric Coil Company
Isolation Transformer – Johnson Electric Coil Company
Three Phase Isolation Transformer – Lenco Electronics, Inc.
Contrary to the popular notion, electric transformers have applications other than increasing and decreasing voltage. They are extensively used as an impedance transferring device, isolation transformers are used to isolate different circuits, and a device that prevents direct current from passing. Apparently, transformers did not become versatile in a short span, they have a long history. To explore any equipment and its working, there is no better way than exploring its history.
Therefore, we are outlining the history of transformers.
The principle on which electric transformers work was first provided by Michael Faraday in the end of 19th century. He was a scientist from England who contributed extensively to electrochemistry and electromagnetism. Many electrical devices that we see in the modern era, more or less, employ his discoveries and concepts. However, some historians give credit to Joseph Henry for proposing the operating principle of transformers. However, Henry’s idea was published later, therefore, Faraday still is considered a better authority on transformers. He said current flowing in the coils produces a magnetic field, which later was distilled as Faraday law of induction, describing the relationship between the voltage or electro motive force and magnetic flux.
To prove the theory, he conducted numerous experiments and made the first closed core transformer by linking two coils around an iron core and inducing a magnetic flux. Until then, induction coils were not invented.
It was an Irish scientist, Nicholas Callan, who first made induction coils and used them to make electric transformers, though used for direct current applications. However, more than his invention, his observation regarding the relationship between the number of turns on coil and voltage produced, pushed the technology forward.
Until then, research was more focused on direct current than alternating current; therefore, it was only in the 1870s, the first working alternating current transformers were invented.
Later in the 19th century, a Russian made a functional electric transformer, who used an induction coil to light up electric candles. His intention was different, but he, like many other inventions, ended up making an alternating current transformers. Soon, open iron core transformers were invented in England, however, the efficiency made them inoperable most of the time.
At that time, there was a great debate among scientist about the use of alternating current over direct current. There were two factions, both convinced that their electric current would pass the test of time. The debate was dubbed as the war of currents, and with the advent of closed core electric transformers and parallel distribution of power, the war was settled for once and all. The alternating current became mainstream source for lighting bulbs and powering equipment, and since the alternating current has maintained its position.
Almost at the end of 19th century, the first closed core electric transformers were patented, and then the battle between the Westinghouse and Edison electric company ensued for the rights of transformers. However, the battle gave the world efficient transformers that we see everyday either at poles or in circuits.More Isolation Transformers Information