What Is an Encapsulated or Potted Coil?
Leave a Comment
An electric coil comprises two distinct components: a conductor and a core. The conductor is typically made of solid copper wire wrapped around a metal core. A turn is created each time the wire is looped around the core, while multiple turns are considered a coil. It acts as an electrical conductor, efficiently sending an electrical current to generators, electric motors, electromagnets, and inductors.
The most common application of an electric coil is as an inductor, which stores energy within its electric field. As a passive electronic component, an inductor has no gain and thus cannot control the directional flow of energy. Instead, it captures energy from the electric current flowing through its body.
Electrical coils are typically required in industrial manufacturing, medical equipment, and devices used to supply electricity to commercial and residential buildings.
Definition of an Encapsulated or Potted Coil
Like any other electrical coil, an encapsulated or potted coil is constructed from a ferromagnetic metal wire wrapped into a specific diameter. It is an electromagnet that is only activated by magnetism when exposed to electric currents. Since most coils use outer casings for protection from harsh environmental conditions — such as salt, water, moisture, and vibration — encapsulated coils are frequently molded into liquid or thermoformed epoxies. This procedure causes the coil to fuse with its casing.
Both encapsulated and potted coils surround and seal the coil with liquid materials, including silicone rubber, epoxies, and polyesters. These materials are available in temperatures ranging from 105 °C to 190 °C. The only difference between the processes for encapsulated and potted coils is the tooling: encapsulation utilizes a reusable mold into which the coil is placed, filled with material, and then removed after curing. Meanwhile, potting uses a single-use cup, which soon becomes a component of the final product.
Advantages of Using Encapsulated or Potted Coils
Encapsulated or potted coils have high dielectric and isolation properties and uniform dimensional and cosmetic characteristics. Thus, they often provide better protection against extreme environmental conditions than molded coils. Besides that, because they are dipped and thermoformed into sealing liquid, epoxies such as silicone rubber provide vibration protection that molded casings do not. Encapsulated coils can also be heat-treated after manufacturing, which sinters the plastic component with the molded coil inside, providing excellent protection.
Moreover, encapsulation and potting processes aid in transferring heat and protect the components from thermal shock and adverse working environments, such as grease, salt, water, humidity, and gasoline. Finally, they provide a cost-effective alternative to overmolding when a protective outer shell is required, as overmolding tooling can be costly and impractical in small volumes.
Endicott Coil Company’s Encapsulated Coil Manufacturing
Endicott Coil Company creates customized encapsulated coils resistant to the harshest environmental circumstances. Depending on the customer’s application, our experts select the best encapsulation material, such as thermoplastics, thermosets, epoxies, silicone rubber, and polyesters.
We are fully equipped with vacuum chambers, vacuum ovens, and curing ovens to achieve a proper cure regardless of the material used.
Our company produces encapsulated coils with temperatures ranging from 105 °C to 240 °C. To ensure that all specifications are met, these coils are extensively tested using hi-pot, inductance, resistance, leak, and surge testing.
High-Quality Custom Coils and Components From Endicott Coil Company
Endicott Coil Company, Inc. has a long history of providing high-quality custom magnetic components and services. Our company leverages our extensive knowledge, expertise, versatility, and capabilities to meet and fulfill each customer’s specifications. We also offer comprehensive value-added services — such as overmolding, encapsulation, and sub-assembly manufacturing — in addition to our wide assortment of coils and transformers.
Our facility is RoHS compliant and employs ISO methodologies and procedures throughout the manufacturing process. Furthermore, we have experience with ASTM, CSA, VDE, NRC, Mil-Spec, and UL testing procedures.
Contact us today to learn more about the products and services Endicott Coil Company offers. You can also request a quote now!
What Is a Self-Supported Coil?
Leave a Comment
An electric coil, also known as an electromagnetic coil, is an electrical conductor composed of wires wrapped around a cylindrical, disk-shaped, or toroidal ferromagnetic core. It is one of the most basic electronic components, providing inductance in an electric circuit. Inductance refers to an electrical property that opposes current flow through the circuit.
Electric coils are widely used in applications where electric currents interact with magnetic fields. These include the manufacturing, engineering, and medical industries. They are also found in devices and equipment such as electric motors, generators, transformers, inductors, and sensor coils.
Definition of a Self-Supported Coil
Self-supported or air core coils are created by coating magnet wire with an adhesive and then wrapping it in an insulating film. Solvents, hot-air heating, and post-baking can all be used to activate the adhesive and secure the adjacent strands of magnet wire. They are also wound on collapsible mandrels, allowing disassembly without damaging the wire insulation. The mandrels can be machined into nearly any shape to accommodate any desired coil configuration.
These coils are ideal for electronic applications where a bobbin or other coil form is impossible due to dimensional constraints. They reduce bobbin costs while increasing copper content in a given area.
Presently, bondable magnet wire with fundamental solutions up to 180° is available. However, the strand-to-strand bond typically begins to soften at temperatures 10° to 15° below the insulation rating. A bondable wire is also useful when magnet wire bonding is preferred to prevent movement or wire abrasion in applications where other processes, such as impregnation or varnishing, are not recommended.
Advantages of Self-Supported Coils
One of the most significant benefits of a self-supported coil is the low signal loss that occurs at higher magnetic field strengths. Ferromagnetic cores such as iron can become magnetically saturated when the magnetic field is too strong, causing an inductance loss. This is not a problem for self-supported coils as they can carry electromagnetic frequencies up to 1 GHz. Conversely, ferromagnetic core inductors lose efficiency once the frequency exceeds 100 MHz.
Self-supported coils are also simple to build since they are unaffected by the value of the electric current they transport. If there is no ferromagnetic core, they are more suitable for low-power devices, such as commodity electronic products, computer devices, communication equipment, and other consumer goods.
CNC Winding of a Self-Supported Copper Coil by Endicott Coil
Endicott Coil Company, Inc. manufactures a wide range of self-supported coil shapes and sizes for use in various space-constrained electronic applications. Based on customer specifications, the company uses CNC equipment to wind strands of coated 24-48 AWG copper magnet wire to the desired shape. The bondable coating is then activated via a solvent or heat cure to secure the magnet wire strand-to-strand.
Endicott also solders and trims the finished pieces using in-process gauging to maintain tolerances of less than 0.005 in.
Partner With Endicott Coil Company for High-Quality Custom Coils and Components
Endicott Coil Company, Inc. has been the leading supplier of magnetic components to a wide range of OEMs for over 65 years! We have earned a solid reputation for value and performance, enabling us to meet and exceed our customer’s needs and expectations.
Our company can significantly help with material selection, parameter testing, and cost-cutting redesigns of existing coil designs. Endicott Coil’s engineering team is also exceptionally skilled and specializes in custom electric coil winding assemblies! We can create and construct any coil type, including self-supported, injection molded, bobbin wound, impregnated, and sensing coils.
For more information on our coil services, contact us right away. You can also request a quote to start your next project with Endicott Coil Company!