Radio Controlled Stuff. Woodworking Plans. Tractors. Lighting For Low Vision. This information is provided by Macular Degeneration Support at www.mdsupport.org . One printed copy is permitted for personal use only. by Dan Roberts with supporting information provided by Roy Cole, O.D. September 2003 What is the best kind of lighting for visually-impaired people? The bottom line is that people should use the lighting that works well for them. The closest to actual sunlight, covering the entire range of colors. Commonly used in the form of a light bulb in table or desk lamps, this is the safest light source for the eyes. Bright and economical, this type of lighting is seen most often in public places. Roy Cole, O.D. For task lighting, the lamp (bulb) should be in an adjustable fixture, and the distance of the light source from the page is as important as wattage. To reduce the heat of the bulb, use a lamp with an internal reflector (a double shade).
Here are some other guidelines from Dr. Place the light directly where you need it. Watch television in a lighted room. Energy Fiend - The Caffeine Fix. The SimCam: Film and Digital Camera Simulator - Photonhead.com. List of screw drives. A is the system used to turn a screw . [ 1 ] [ 2 ] At a minimum, it is a feature on the screw that allows for it to be turned. Usually it also involves a mating tool , such as a screwdriver , that is used to turn it. The following heads are categorized based on commonality, with the less common drives being classified as "tamper-resistant". Most heads come in a range of sizes, typically distinguished by a number, such as "Phillips #00" or "Torx T5". These sizes are not characterized by a linear dimension, but are arbitrary designations in the same sense as a "Size 8" shoe or dress. [ edit ] Common types [ edit ] External types All of these screw drives are characterized by a female tool and a male fastener. [ edit ] Square A screw drive uses square fastener heads.
A screw drive uses six-sided fastener heads. . [ edit ] Pentagon A screw drive uses five-sided fastener heads. . [ edit ] Thumbscrew [ edit ] Slotted types Blade width Fastener size 3 ⁄ 32 in (2.4 mm) 1 ⁄ 8 in (3.2 mm) 5 ⁄ 32 in (4.0 mm) AC power plugs and sockets. Plugs and sockets may sometimes combine male and female contacts, but the exposed pins or terminals in the socket are not energized. (clockwise from top left: German CEE 7/4 plug and socket, French CEE 7/5 socket) AC power plugs and sockets are devices that allow electrically operated equipment to be connected to the primary alternating current (AC) power supply in a building.
Electrical plugs and sockets differ in voltage and current rating, shape, size and type of connectors. The types used in each country are set by national standards, some of which are listed in the IEC technical report TR 60083, Plugs and socket-outlets for domestic and similar general use standardized in member countries of IEC.[1] Plugs and sockets for portable appliances started becoming available in the 1880s, to replace connections to light sockets with easier to use wall-mounted outlets. A proliferation of types developed to address the issues of convenience and protection from electric shock. History[edit] Get in Shape with Tech, Trim the Fat from Android, and Speed Up Your Computer with an SSD. Top 10 Repair Projects You Should Never Pay For. AC power plugs and sockets. Top 10 Rule-Breaking Projects, Upgrades, and Solutions That Are Better Than Off-the-Shelf Products. Coaxial power connector.
Most common coaxial power connector, male and female, 5.5 x 2.5 mm Common DC power connectors A coaxial power connector is an electrical power connector used for attaching extra-low voltage devices such as consumer electronics to external electricity. Also known as barrel connectors, concentric barrel connectors or tip connectors, these small cylindrical connectors come in an enormous variety of sizes. Barrel plug connectors are commonly used to interface the secondary side of a power supply with the device. Some of these jacks contain a normally closed switch; the switch can disconnect internal batteries whenever the external power supply is connected. Connector construction and terminology[edit] Female (plug)[edit] On the female plug, the outer body is a one metal contact. Male (receptacle)[edit] There is typically a single spring-loaded contact at the side of the male connector and a pin in the center corresponding to the intended female plug.
Connector sizes[edit] Standards[edit]