optyka: Headlamp

Evidence: 100 • authority: 72

A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in United States usage, headlamp is the term for the device itself and headlight is the term for the beam of light produced and distributed by the device. Headlamp performance has steadily improved throughout the automobile age, spurred by the great disparity between daytime and nighttime traffic fatalities: the US National Highway Traffic Safety Administration states that nearly half of all traffic-related fatalities occur in the dark, despite only 25% of traffic travelling during darkness. Other vehicles, such as trains and aircraft, are required to have he…

Evidence: 54 • authority: 72

A mechanically powered flashlight is a flashlight that is powered by electricity generated by the muscle power of the user, so it does not need replacement of batteries, or recharging from an electrical source. There are several types which use different operating mechanisms. They use different motions to generate the required power; such as squeezing a handle, winding a crank, or shaking the flashlight itself. These flashlights can also be distinguished by the technique used to store the energy: a spring, a flywheel, a battery or a capacitor. Since they are always ready for use, mechanically powered flashlights are often kept as emergency lights in case of power outages or other emergencie…

Evidence: — • authority: 72

A hub dynamo is a small electrical generator built into the front hub of a bicycle wheel that is usually used to power lights. Often the hub "dynamo" is not actually a dynamo, which creates DC, but a low-power magneto that creates AC. Most modern hub dynamos are regulated to 3 watts at 6 volts (likely due to StVZO requirements), although some will drive up to 6 watts at 12 volts.

Evidence: — • authority: 72

In electricity generation, a generator, also called an electric generator, electrical generator, and electromagnetic generator is an electromechanical device that converts mechanical energy to electrical energy for use in an external circuit. In most generators which are rotating machines, a source of kinetic power rotates the generator's shaft, and the generator produces an electric current at its output terminals which flows through an external circuit, powering electrical loads. Sources of mechanical energy used to drive generators include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. Generators produce nearly all of the el…

Evidence: — • authority: 72

A dynamo is an electrical generator that creates direct current using a commutator, and uses self-powering electromagnets for the stator field rather than permanent magnets. Dynamos are self-starting by using residual magnetic field left in the iron cores of the electromagnets (i.e. field coils). If a dynamo were never run before, it was usual to use a separate battery to excite or flash the field of the electromagnets to enable self-starting. Dynamos were the first practical electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alterna…

Evidence: — • authority: 72

A bottle dynamo or sidewall dynamo is a small electrical generator for bicycles employed to power a bicycle's lights. The traditional bottle dynamo (pictured) is not actually a dynamo at all (which creates DC power), but a low-power magneto that generates AC. Newer models can include a rectifier to create DC output to charge batteries for electronic devices including cellphones or GPS receivers. Named after their resemblance to bottles, these generators are also called sidewall dynamos because they operate using a roller placed on the sidewall of a bicycle tire. When the bicycle is in motion and the dynamo roller is engaged, electricity is generated as the tire spins the roller. Two other d…

Evidence: — • authority: 88

Tsunami: Ocean dynamo generator. Abstract Secondary magnetic fields are induced by the flow of electrically conducting seawater through the Earth's primary magnetic field (‘ocean dynamo effect’) and hence it has long been speculated that tsunami flows should produce measurable magnetic field perturbations, although the signal-to-noise ratio would be small because of the influence of the solar magnetic fields. Here, we report on the detection of deep-seafloor electromagnetic perturbations of 10-micron-order induced by a tsunami, which propagated through a seafloor electromagnetometer array network. The observed data extracted tsunami characteristics, including the direction and velocity of p…