From a technical perspective, an electro-mechanical assembly is a device designed to use electrical current followed by transforming it into some type of operation according to specific work. Among these assemblies are a few different options with the most common being the relay.
With a relay, an electromagnetic that causes the opening or closing of a switch based on design is energized via electrical current. It is common for a relay to be used by engineers so circuits can be turned off and on whenever needed.
There are some instances in which a relay is used in a different way. It can switch higher current circuit other than what the sensor that operates the relay is capable of carrying. For instance, in more modern day automobile manufacturing, this particular type of electro-mechanical assembly would be the preferred choice.
With modern vehicles, behind the radiator is one, if not two electrical fans. A temperature sensor designed within the cooling system of the engine is what turns the fans off or on. However, the amount of current the fans draw is more than the wires coming from the sensor can handle so in order to prevent the wires from becoming overloaded, the sensor is routed to a relay whereby the fan can be turned off or on.
In other words, the relay, which is a type of electro-mechanical assembly, is designed to carry a heavier load of current to ensure everything works as it should but also in a safe manner.
Another commonly used type of cable assembly is known as the overload protection relay. Typically, this relay is used in the design of high-dollar electronic equipment. While an overload protection relay is a simple device it has the ability to prevent a piece of equipment that costs millions of dollars from being damaged if a circuit should become overloaded.
This type of relay is often used in electric motors as a means of shutting down the system if the operating temperature of the motor reaches a level deemed too high. With this, two bi-metallic strips within the device release a spring that holds together the power contacts whenever they reach too hot a temperature.
As part of designing an electro-mechanical assembly, an engineer will begin by creating a device capable of performing a particular task. Usually, CAD software is used to create a drawing, the device is built, research performed, and a feasibility study done to determine the cost of building the assembly.
From there, a prototype is developed, a working model created, and further study conducted. A report on the electro-mechanical assembly is generated that goes over materials used and the process needed in order to take the device into full production.