Multilayer PCB

Initially, electronic components were available in DIP packages only and PCB boards were used to be large-sized, thus having more space for the PCB wirings/connections. But with the research in nanotechnology, electronics get introduced with SMD(Service Mount Device) components. SMD components are very small-sized components and their sole purpose is to reduce the overall size of electronic kits/circuits. So, now when SMD components are used in PCBs, they are placed very close to each other, and in complex designs, there's not enough space to pass the tracing lines of connection wires. So, to overcome this issue, Multilayer PCBs are introduced, where connections/wirings are split across different PCB boards(called layers) and these layers are laminated to keep insulated from each other and glued together. So, any PCB having 3 or more layers is termed a MultiLayer PCB.

• A PCB is called Multilayer PCB if it has 3 or more layers(sheets) of copper foil, insulated from each other(by lamination or coating) and joined together to form a single piece.
• A Multilayer PCB has an Inner Layer Core present at the center of all the layers and coated with a Copper layer from both sides, while layers of prepreg(woven glass cloth with epoxy resin) are used for insulation.
• In Multilayer PCB, outer layers(top & bottom) are single-sided PCBs, while the inner layers are double-sided PCBs.
• In multiplayer PCBs, few layers might be assigned with fixed tasks and are termed as planes i.e. power planes, ground planes.

                                          Multilayer PCB

IoT

• The IoT harnesses the power of the internet to connect physical devices in real-time. So any physical object connected through the internet can be converted into an IoT device. For example, how are you reading this article… over a smartphone, tablet, or PC? You’re already connected through the internet and are using an IoT device.
• Similarly, a light bulb, which is a physical object itself, will be considered as an IoT device when connected through a smartphone app to turn it on and off. IoT examples may include washing machines, refrigerators, watches, laptops, phones, cars, and pretty much everything we can connect with the internet.
• Generally, the internet of things examples include quick access to the appropriate information at the right time, be it related to exercising, traveling to a meeting, socializing, shopping, or visiting a doctor.
• Sensors are a crucial part of the IoT network. That means millions of sensors connected through IoT sensor technology worldwide to collect a rich set of context-aware and informational data including images, location, and weather conditions, and inject into the networks and applications for the data processing.
• IoT can help connect the people living in the remotest corners of the world. Plus with devices functioning at incredibly low power, IoT provides solutions without risking the system’s accuracy. This is possible since at the smallest level we can incorporate these things with smart technology for them to communicate over the internet.

• Don’t see IoT as an individual system, but as an integrated infrastructure that can handle many services and applications at a time. Such applications include city-wide activities like efficient transportation systems, waste management systems, others include worldwide activities like global delivery systems, security systems while others include personalized activities like bridging the gap between the digital world and physical world.

                                           What is IoT?

LM317

LM317 is a positive voltage regulator with three different terminals Adjust, Vout, and Vin respectively. It can supply the output voltage in a range of 1.25-37V and a current of more than 1.5A. It has advanced line regulation and load regulation standards as compared to the general regulators. It has a lot of applications in real life e.g. motor controllers, power bank solutions, hydraulic valve, ethernet switch, battery chargers, etc.

LM317 Working Principle

LM 317 works on a very simple principle. It is a variable voltage regulator i.e. supports different output voltage levels for a constant applied input voltage supply. A variable resistor is connected at its Adjustment (Adj) terminal in order to control the level of the output voltage according to the requirements of the circuit. In other words, we can say that LM 317 can step down the voltage from 12V to several different lower levels.

LM317 Pinout

• LM 317 has three (3) pins in total Adjust, Vout, and Vin respectively.
• Each of the pins has its own functions, all the pins along with their name and numbers are shown in the table given below.

LM317 Applications

LM 317 has a very wide range of applications, a few of which are given below.

• Washing machine.
• Waveform generator.
• Refrigerator.
• Programmable Logic Controller (PLC).
• Power quality meter.
• Motor controllers.
• Fingerprints.
• Ethernet switch.
• Private branch exchange.
• Constant current regulators.
• Microprocessors supplies.
• Automotive LED lighting.
• Battery chargers, the proper design of the circuit is shown in the figure below.

                                             LM317 Pinout