Power Supplies & Circuit Protection
Power refers to the energy that is converted or transferred per unit time. It is the rate at which energy is transferred or work is done. The standard unit of power is watt, which goes by the symbol “W”. It is named after James Watt, a Scottish industrialist and inventor. One watt is equivalent to one joule of completed work per second. Power is measured in two ways: average and instantaneous.
Batteries & Chargers
Batteries have electromechanical cells that are equipped with external connections. It is essential in providing power to electrical devices like mobile phones, flashlights, and even cars. Batteries have a negative terminal called anode and a positive terminal known as cathode. The anode is where the electrons that travel to the external electric circuit and through to the cathode come from.
Batteries store and then discharge energy when it converts chemical energy to electricity. There are three major types of batteries:
- Dry cell rechargeable (for mobile phones, cordless appliances, and power tools, among others)
- Dry cell non-rechargeable (household batteries)
- Wet cell batteries (for industrial and automobile use)
Chargers are devices that send electric currents to batteries so as to transfer energy to them. There are four main classifications of chargers:
- Solar chargers
- AC adapters
- USB chargers
- Car chargers
Circuit protection refers to the intentional addition of a weak link into an electrical circuit. When there is a fault, this link will break and serve as protection for the electrical circuit, helping prevent dangers (such as fire). A weak link may be broken by a conductor short circuit, excessive current, or high temperature. The most common circuit protection device (CPD) is the circuit breaker or fuse.
Power & Line Protection
Power protection devices are used to provide safety for sensitive equipment, specifically in instances where there are power surges and power failures. These devices help prolong the life of electronics and equipment through proper distribution of power, power backup, minimizing plug inconveniences, and providing an alternative power source. Some examples of power protection devices are UPS or Uninterrupted Power Supply, surge protectors, power strips, power inverters, and power distribution units.
Line protection devices work like power protection devices, including keeping overhead lines safe. Common incidents that could lead to overhead lines faults include lightning, birds (and other animals) hitting distribution transformers, automobile and aircrafts hitting a power line, wind, trees, snow and ice loading, and contaminated / broken insulators.
Transformers are passive electrical devices that use wire coils to transfer electrical energy from one to another, or to multiple circuits. It helps supply more voltage to loads in need of more current. The capacitor transformer, electromagnetic transformer, and optical transformer are the three main types.