valve, in mechanical engineering, device for controlling the flow of fluids (liquids, gases, slurries) in a pipe or other enclosure. Control is by means of a movable element that opens, shuts, or partially obstructs an opening in a passageway. Regulation Valves: Ball, butterfly, diaphragm, globe, needle, pinch, and plug valves. Safety Relief Valves: Pressure release and vacuum relief valves. Non-Return Valves: Swing check and lift check valves. Special Purpose Valves: Multi-port, float, foot, knife gate, and line blind valves.
All of the most common types of automated valves fall into one of three main categories. They are linear, rotary, and self-actuated. There are a variety of valve types within each of these categories each having its own benefits. This training course is focused on rotary and linear actuated valves.
A transmitter is an electronic device used in telecommunications to produce radio waves in order to transmit or send data with the aid of an antenna. The transmitter is able to generate a radio frequency alternating current that is then applied to the antenna, which, in turn, radiates this as radio waves. The transmitter combines the information signal to be carried with the radio frequency signal which generates the radio waves, which is called the carrier signal. This process is called modulation. The information can be added to the carrier in several different ways, in different types of transmitters.
