Which Transformers Are Best For Electrical Isolation In Medical Devices - Miracle Electronics

 With a multitude of transformer options available, identifying the best one out of the lot becomes difficult, for every individual application. And, the application that we are going to speak about in this blog is a critical one – medical devices. No kind of fault can be afforded in the case of medical applications. This is why only the most ideal kind of transformer that can offer safety and protection against electrical surges should be used. So, which one is it?

Toroidal transformers is the answer. Toroidal transformers are ideal for electrical isolation in medical equipment as they are compact, have low stray fields, and can be encapsulated when required. Hence, these transformers are less likely to cause electromagnetic disturbances. Isolation is when two parts of a circuit are physically and electrically separated, which is achieved by using electromagnetic field coupling between the two circuits. Isolation provides several safety advantages like breaking ground loops, improving common-mode voltage rejection, and permitting the two parts of the circuit to be at different voltage levels. For an isolation method to be safe enough for use in medical equipment, it needs high-integrity isolation components and a safe insulator barrier. The three most commonly used isolation methods include transformers, capacitive couplers, and optocouplers. But, in this blog, we will focus on the use of transformers to electrically isolate medical equipment.

A transformer transfers energy between two or more circuits through electromagnetic induction. They increase or decrease the voltages of alternating current in electric power applications, by passing a varying current through the primary winding to generate a magnetic flux in the transformer’s core, which in turn induces a voltage in the transformer’s secondary winding.

Toroidal cores are made form a continuous strip of silicone steel wound like a tight clock spring, with the ends tacked into place with small spot welds to prevent the coiled steel from unwinding. The core is insulated with an epoxy coating or a set of caps or multiple wraps of insulating film. The transformer’s windings wound around the core require additional insulation to be isolated. However, the construction of a toroidal transformer is very labour-intensive. But yet, these transformers are preferred more than any other transformer because of its performance. With the continuous strip of steel used in the core, the transformer becomes smaller, lighter, more efficient, and quieter than other kinds of transformers. These qualities are the most apt for sensitive medical electrical equipment; and clearly justify the additional expense.

Thus, to conclude, toroidal transformers are ideal for electrical isolation in medical equipment. So, if you are looking for the perfect transformer for your application, just get in touch with Miracle Electronics, a reliable and reputed medicaltransformer manufacturer in India, who can provide you with the most ideal toroidal medical isolation transformer . And, you can rest assured about the quality of transformers you will get here because every medical isolation toroidal transformer you’ll get will be RoHS and REACH compliant, adhering to the regulations under UL 60601-1 standards.

Switch Mode Power Supply Transformers _ What They Are - Miracle Electronics

 Switched mode power supply (SMPS) is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently, by transferring power from a DC or AC source to DC loads. The pass transistor of an SMPS continually switches between low dissipation, full on, and full off states, spending very little time in the high dissipation transitions, which minimizes wasted energy. Also, by varying the ratio of on to off time, voltage regulation is achieved. This high power conversion efficiency with no energy wastage is an important advantage of an SMPS.

Unlike linear power supply transformers, SMPS are small and light due to the smaller size and weight of the transformers installed, which is why they are effectively used as replacements for linear regulators when high efficiency is required with lighter weight and smaller size. The transformers that are mainly composed of magnetic core and winding, are used for conversion, energy storage, and isolation. But, the materials used will affect the performance of the transformer, which will in turn affect the heat dissipation and working efficiency of the equipment. Thus, you need to be very sure about the materials that you are having installed in your SMPS transformer. This is why when planning on getting an SMPS transformer for your application, you need to approach only an expert transformer manufacturer in India, one like Miracle Electronics, who has immense knowledge about, and enough experience of manufacturing and working with SMPS transformers.

Advantages and disadvantages of using SMPS transformers

• One of the main advantages of using SMPS transformers is that you can have efficiency up to 96% because the switching transistor dissipates very little power when acting like a switch. Other advantages include small size, light weight, and low noise. Also, the standby power loss is very low.
• One disadvantage is that they are very complicated and they can cause electrical noise problems if not carefully suppressed; thus causing harmonic distortion.

Types of SMPS transformers

SMPS transformers are divided into two types – unipolar and bipolar. Unipolar transformers are characterized by a unipolar pulse as input voltage, and are divided into positive flyback voltage output. Bipolar transformers are characterized by a bipolar pulse as input voltage, with the output generally being bipolar pulse voltage. 

Materials used

As mentioned above, it is very important to choose the right materials for the SMPS transformer. There are three main components of an SMPS transformer – magnetic materials, wire materials, and bobbin materials.

Magnetic materials – These are soft ferrite which are divided into two categories according to their composition and application frequenct – MnZm and NiZn.

Wire materials – Polyurethane and polyester enameled wires are generally used to wind small electronic transformers, divided into thin paint and thick paint types, depending upon the thickness of the paint layer.

Bobbin materials – Bobbins of SMPS transformers are different from general transformers, as they play a dual role of mounting and positioning of the entire transformer, along with insulating and supporting the coil. Thus, the bobbin material needs to meet insulation requirements, as well as possess tensile strength and heat resistance.

Why Should You Opt For Core Cap Transformers - Miracle Electronics

The typical method of manufacturing a transformer involves creating a core, insulating it, winding a magnet wire around to create a primary winding, insulating it, winding a magnet wire over the insulation to create a secondary winding, and finally insulating it too, to complete the transformer.

What are core caps?

To support the primary and secondary windings, and to reduce leakage current, segmented core caps are used in alternate sectors. Several modular electrically insulating segments snap or join together to form core caps for covering the transformer core. These core cap modules insulate the windings from the core over the full range of windings, allowing double-wall insulation between adjacent windings, significantly reducing leakage current. They also help in direct cooling of the core by ambient or forced air, without interfering with the insulation. The segments of each module include a pair of spaced insulating walls between which a core-covering panel portion is connected. The walls are inclined at a predetermined angle to each other, typically 30, 45, or 60 degrees, which is what determines the number of segments required to complete one core cap.

Benefits of using core caps

Reduced time invested – With the installation of core caps, there is no need for ground and inter-winding insulation and outer wrap. Also, both the primary and secondary windings can be wound on one machine only. In addition, providing the core cap includes mounting holes, which means that the time to fill the center of the transformer with epoxy is not required. All of this results in lesser time invested to manufacture and handle the transformers.

Reduced weight of the transformer – As mentioned above, there is no epoxy required to fill the center of the transformers if core caps are installed. Besides, no mounting washer will also be necessary. Hence, the weight of the transformer is also considerably reduced.

Reduced costs – Assembling core caps requires lesser skill levels that other core insulation techniques. Also, the cost to tool a smaller part for injection moulding is lesser than the cost of tooling a larger part. Thus, the cost to tool and assemble the core caps is way lesser. This means that the overall manufacturing costs of the transformer will be lesser too.

Reduced temperature rise – With core caps, there is a direct path for heat to escape into the environment. There is also no inter-winding insulation and outer wrap that traps heat. Thus, with all windings having a direct path for heat to transfer to the environment, then the temperature rise of the transformer is also reduced.

As you can see, core cap transformers help with reducing the time, weight, and costs of the transformer to a considerable extent, while also reducing the heat buildup. So, it can be clearly seen why core cap transformers are much better than standard transformers. You now know which kind of transformers to opt for, for your next application.

No matter what industry you are working in, and what kind of transformers you need, Miracle Electronics is your one stop destination to design all your transformer requirements. You can get all kinds of bundles of massive energy from this power, toroidal, EI, UI, SMPS, audio, and medical transformer manufacturer in India. And, every transformer you receive will always be RoHS and REACH compliant, having you to worry less about its quality and performance.