An innovative technique to greatly reduce the size and cost of electromagnetic switches and circuit breakers,
which are widely used in homes and industries, has been developed by MIT Creative Research Center at ETRI.
The research center utilized the Mott Metal-Insulator Transition phenomenon that was demonstrated in 2005.
The Mott Metal-Insulator Transition phenomenon shows that an insulator can be converted into a metal, or a metal can serve as an insulator.
This was a revolutionary discovery that even an insulator can conduct electricity.

The research center led by Dr. Hyun-Tak Kim at ETRI applied the MIT phenomenon
to a chip embedded in electrical devices to interrupt an electric current in case of overcurrent.
The center removed the relay part from an electromagnetic switch and substituted it with a MIT device,
which allowed makes available to applying the device widely for interrupting electricity
even in low voltage wiring circuit breaker and ground fault circuit interrupter and the like.
An existing traditional electromagnetic switch that takes the role to interrupt electricity
when it conducts an overcurrent is composed of the magnetic contactor
which connects or disconnects signals of main power and the over-load relay, which is an on-off switch.

The MIT chips attached to a printed circuit board (PCB) was substituted
for the overload relay part of an electromagnetic switch in ETRI,
which has passed an overcurrent interrupting test at Korea Testing Certification.
And the center is planning to mount the MIT device in the magnetic contactor part, therefore, taking off the relay part
from the components of an existing traditional electromagnetic switch makes possible to halve its size and cost.

ETRI forecasts, for example, the electromagnetic switch in an air conditioner which is now on the market,
is priced for $20~$30 and its relay is priced for about $10, therefore if the relay
would be substituted by an MIT device, the electromagnetic switch would be halved in price.

Dr. Hyun-Tak Kim says “The circuit is very simple and doesn’t use a big mechanical
point of contact so we can greatly decrease the volume and enhance reliability.”

The technology can be adapted to not only washing machines, refrigerators,
air conditioners, and firefighting pumps, but also motor products based on alternating current
whose direction and power of current changes based on time, such as earth leakage breakers.
The devices will also feature significantly reduced size and cost because they contain sensors
and an internal switch function. It is expected that the global market for electromagnetic switches
and circuit breakers is worth approximately $29.5 billion in 2016.