How inductors enable miniaturisation in electronic devices
Faster, cheaper and lighter electronic devices continue to fuel the need for smaller electronic components. Because of this need for miniaturisation, designers are now developing ultrasmall inductors that are efficient and enhance the life of electronic p
An inductor is a basic, passive electronic component that caters to many sectors including consumer electronics, telecommunications, military and automobiles. Inductors are widely used for high power applications, noise suppression, signal processing and voltage stabilisation. As it is impossible for a single inductor to perform all these functions, various types of inductors are designed and used for these diverse applications.
A choke is a type of inductor that is used for choking off or blocking high frequency or alternating current (AC) from entering an environment where low frequency or direct current (DC) is required. Coils of a relay also act as an inductor and control the flow of current in it. Inductors, when used in combination with capacitors, act as a filter and separate the signals of different frequencies. That helps to make tuned circuits, which are used in radio and TV broadcasting. Other types of inductors include transformers, ferrite beads and power inductors.
The shrinking motherboards of the next generation electronic devices are pushing inductor makers to weave improved performances into ever-tinier packages. Most technological developments in inductors these days are happening around size reduction and are yielding some impressive results.
One of them is the thick- or thin-film construction technique that replaces the age old copper wire winding that was earlier used as an inductor. This technique not only significantly reduces the physical size and weight of inductors but also offers drastic improvements in key parameters such as Q factor, self-resonant frequency, tolerance and inductance.
Power chokes, used largely in line filters, power supplies and DC/DC converters, are also moulded in a mini form to serve the need for smaller sizes. Mini moulded chokes are mostly used in smartphones and tablets for sleeker designs, improved battery life and power management.
Another tech advancement in the handheld devices category is the development of 2-in-1 inductor array products, which enable more effective use of the limited circuit space.
Domestic manufacture of all types of inductors is facing an acute setback due to unavailability and constant variation in the prices of raw materials, and there is a great reliance on imported inductors at present. Anil Batra, managing director, Indian Technological
Products Pvt Ltd, says, “Relays (or inductors) are made in a highly automated production facility, wherein coil winding, assembly and testing are all automated. There is intense competition today from imported relays, as the Indian production base is not able to take advantage of the economies of scale. Like any other industry, this industry is also totally driven by price; local companies are relying heavily on imports because they are getting an unrestricted supply of good quality relays at a relatively low cost.”
However, he points out the risk factor when the buyer bases procurements primarily on price. “There are some manufacturers in China who keep on diluting the specifications if the customer continues asking for a lower price. Therefore, it is important to base the purchase on consistent quality as well as on price,” he adds.