Search results
Results From The WOW.Com Content Network
A sprinkler system timer is an electrical device that is used to set an irrigation sprinkler system to come on automatically at a certain time. Irrigation timers first appeared in the early 1960s to control large-radius lawn sprinklers, which at the time usually contained their own electrically operated valve (most golf-course sprinklers still use this type of actuation).
Rain sensors for irrigation systems are available in both wireless and hard-wired versions, most employing hygroscopic disks that swell in the presence of rain and shrink back down again as they dry out — an electrical switch is in turn depressed or released by the hygroscopic disk stack, and the rate of drying is typically adjusted by controlling the ventilation reaching the stack.
The timer may switch equipment on, off, or both, at a preset time or times, after a preset interval, or cyclically. A countdown time switch switches power, usually off, after a preset time. A cyclical timer switches equipment both on and off at preset times over a period, then repeats the cycle; the period is usually 24 hours or 7 days.
The Rain Bird horizontal action impact-drive sprinkler head was recognized as a historic landmark of agricultural engineering in 1990 by the American Society of Agricultural and Biological Engineers. [3] This invention led to sprinkler irrigation development that currently exceeds 50,000,000 acres (78,000 sq mi; 200,000 km 2) worldwide.
Micro-irrigation, sometimes called localized irrigation, low volume irrigation, or trickle irrigation is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Traditional drip irrigation use individual emitters, subsurface ...
A typical kitchen timer. A timer or countdown timer is a type of clock that starts from a specified time duration and stops upon reaching 00:00. An example of a simple timer is an hourglass. Commonly, a timer triggers an alarm when it ends. A timer can be implemented through hardware or software.
An example of on/off toggle light switches mounted on a wall. A toggle light switch is a switch, most commonly used to operate electric lights, permanently connected equipment, or electrical outlets whereby the switch handle does not control the contacts directly, but through an intermediate arrangement of internal springs and levers.
Drawing up a comprehensive list of words in English is important as a reference when learning a language as it will show the equivalent words you need to learn in the other language to achieve fluency.