The power transformer

Power transformer is a static machine used in transmission network. It helps in transmission of power from one network to the other without change in frequency. These transformers operate at high or peak load and have maximum efficiency at full load. One of the key concerns in transmission of power is transmission loss. Power transformers allow transmission of power over long distances at high voltages, thus minimizing the transmission loss. Over the years, there has been a significant increase in the transmission voltages whereas generation and distribution voltages have remained constant. Power transformers have allowed this shift from low-voltage power transmission to high-voltage power transmission.
The power transformer (<100 MVA) market is currently in the growth stage, majorly for large transformers. Increase in demand for power, cross border power transmission, initiative to utilize more renewable and non-conventional energy sources, smart grids, and need to upgrade transmission networks boost the power transformer (<100 MVA) market. Utilization of ultra-high voltage transmission technology in the developing economies such as China and India demonstrate increase in importance of power transformers. However, high transformer cost as well as cost of protection instruments and supporting infrastructure prevents optimal utilization of power transformers throughout the region.

Why the wooden kitchen cabinet is back in vogue

Not so long ago, the sleek, handleless kitchen was the epitome of modern style. When minimalism held sway, a streamlined space with high-spec integrated appliances and all clutter packed behind uniform cabinet doors (save for the odd artfully placed vase of flowers or potted herb) was the design blueprint, in city apartments and suburban semis alike.
Over the past few years, however, as we’ve gravitated towards natural materials and more personalised spaces, the traditional, rustic-style kitchen has started to make a comeback – free-standing units, visible utensils and all – and it is surprisingly well-suited to modern urban spaces.
Kitchen designer Tom Howley credits a growing appreciation for craftsmanship to demand for more rural-style, wooden kitchen cabinets; his Hartford range starts from £40,000.
“Many customers are now understanding the work that goes into making a kitchen, which revolves around the desire for quality and performance, longevity being a key driving factor when investing in a kitchen,” he says. “A high-gloss, handleless kitchen is a trend-based buying decision, but a classic shaker-style kitchen can be easily updated.”
In practical terms, any marks or scratches can be sanded down or painted over, and a simple paint job can create a completely new look: a wooden cabinet door may have rustic associations, but painted navy blue or deep teal, it looks altogether more modern and sophisticated. Changing the handles is an even easier update: brass, matt black and leather are on-trend finishes.

As open-plan and broken-plan continue to be the layout of choice, the kitchen island remains popular as a transitional element between kitchen and sitting room. Howley reports that an island was specified in 75 per cent of his kitchen designs last year, and that it doesn’t have to be big to become a social hub.

It’s also a product of the growing popularity of restaurant-level cooking and, in particular, baking at home: maximum worktop space is top of kitchen-buyers’ wish-lists, and we’re increasingly opting for traditional materials such as marble (perfect for pastry-making) and granite, over man-made materials like Corian.
Similarly, more and more of us are opting for a range cooker, the mainstay of a country kitchen – whether or not we live in a country house.

What are 18650 li-ion cells?

What are 18650 battery?
18650 li-ion cells are cylindrical rechargeable cells, shaped like giant AA alkaline batteries. They have a higher nominal discharge voltage of 3.7V, which gives them a signifcant power advantage over the older alkaline(1.5V) and nimh/nicad(1.2V) chemistries. 18650 li-ion cells can be found in laptops, power tool battery packs, electric cars and countless consumer goods.

Why are they called 18650 battery?
The term 18650 comes from the IEC naming scheme for round cells based on their physical dimensions. The first two digits are its diameter in millimeters, while the last 3 digits are for its height in 1/10th millimeters. Based on this naming convention, the original 18650 cells would be 18mm in diameter x 65.0mm in length.

What does PCB protected mean?
Most modern raw lithium-ion cells contain passive safety features like PTC (pressure, temperature and current) protection, however the cells may still be damaged if they are over-charged or over-discharged. To reduce the risk of damage, battery manufacturers will add a tiny circuit board (PCB) to the bottom of the raw cell to monitor its voltage and disconnect power if it senses an error. The protection PCB usually adds 2-3mm to the length of the cell, and the small metal band connecting the PCB to the positive terminal will add a ~0.5mm bulge to its diameter.

What is the difference between a button-top vs a flat-top cell?
Button top cells have a positive terminal that protrudes 1-2mm (ie, the "button"), similar to the positive terminal on AA batteries. The button allows the cells to be stacked in series in a flashlight or similar consumer device. In contrast the positive terminal on a flat-top cell does not protrude, and are intended to be tack-welded into a larger battery pack. If a flat-top cell is used in a device that only accepts button-top cells, the flat-top might not form a reliable electrical connection.