All of our electronic devices designed by combining various electronic components. Each of the components has a specific function. If we take a simple example of lighting one LED by battery, we will connect one wire of LED directly to battery terminal and other wire with a resistor. We will connect another point of resister directly to another terminal of battery.
Now battery will provide electrical energy, LED will produce light and resistor will protect LED by reducing the current. If we will remove the resistor then LED will burn out because electron flow will increase through LED.
Inside a LED a tiny thin wire component available. This will allow a certain amount of electrones to flow. If electrons flow exceeds from its capacity then it this will burn out.
If we see normal cables, it’s thickness is more so it can allow more current to flow. Based on the current flow requirements, wire thickness changes. Current can be decreased by using a resistor in the circuit.
How does resistor work?
The resistor is made by less conductive material. This material restricts the movement of copper-free electrons. It creates a collision in electrones inside the resistor and due to these collisions heat generates.
If we see a working resistor through a Thermal imaging camera then we can observe that it’s producing heat. Some components like MOSFET ( Metal Oxide Silicon Field Effect Transistor). IGBTs ( Insulated- Gate Bipolar Transistor ) produces a huge amount of heat.
Why electronics need cooling?
Every component has a certain Thermal limit. This is called maximum operating temperature. If the current exceeds then heat will generate. If the component temperature goes beyond its limit, it will burn out.
If we take the example of IGBT. As the temperature increases then the current passing through them also increases. This increase in current will again increase the temperature more.
Finally, our IGBTs reaches thermal runaway. This will lead to the destruction of components as well as Circuit Board ( PCB ). So as a preventive action to increase the life span of the component as well as to keep the components operating, stable and reliable, we need to move this thermal energy which components generate. In this way, we are cooling the circuits.
How to remove the thermal energy of the components?
Some components will function normally in room temperature. As the circuit size increases, heat generation also increases. Ways to move the thermal energy from components are given below-
1. Fan –
We can use a simple fan to create airflow between the components. This airflow moves the heat from the components.
Ex: In our Computer CPU a fan is available. This fan moves thermal energy from Motherboard components.
When we are using fan for moving the component’s heat, it can heat up other components also by moving one component heat to another component. It depends on circuit design. That’s why we need to design our circuit by seeing all aspects and impacts.
2. Heatsink –
In this way, we are using one aluminium E shaped object. On its flat side, we paste the components, which is producing most heat. In this way component surface area increases. More area can release more heat and our components can cool down easily. Mostly we are using this way with MOSFET. We can use a combination of Heatsink and fan if heat generation is more in our circuit.
3. Heat Pipe or Vapour Cooling Chamber –
We can see these pipes in our Laptops nearby processor. These are made by copper and there is a liquid inside this pipe. As our component or processor heats up, this liquid will evaporate and convert into vapour. This vapour moves till another end of the pipe. At this end of pipe, we will install a fan for cooling. When this vapour cools down then it converts into liquid again. This liquid again reaches near to processor. Same cycle repeats again and again. In this way, Laptop processor cools down.
We are using Vapour Cooling Chamber Mechanism in latest mobile phones also. Go through the link for more information and read about this new technology in mobiles.
4. Water Cooling –
This method we are using in some latest gaming laptops. In this, we are using a pump, water pipelines and a radiator. We use a heat exchanger that moves motherboard heat into water flowing through pipelines.
This hot water goes to the radiator and cools down. Again this cold water flows near to motherboard and heats up. This cycle repeats and motherboard cool down. This method is majorly used in Power electronics. Where we are using banks of IGBTs. These banks of IGBTs generates a huge amount of heat.
To operate these devices effectively and reliable for a long time, we are using this method. This is the latest technology for circuit cooling.
From these ways, we can select anyone as per our requirement for cooling for our electronics gadgets internal circuitry.
Hope you like this blog.