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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).
The gearbox in a ball valve timer makes a rumbling sound when actuated. The solenoid type switching timers contain a solenoid that relieves pressure on a diaphragm in the water-flow tube or moves a stopper into the water flow area to regulate flow. The solenoid type uses no gears and makes a tapping sound when the solenoid is activated.
The ring circuit is still the most common mains wiring configuration in the UK, although both 20 A and 30 A radial circuits are also permitted by the Wiring Regulations, with a recommendation based on the floor area served (20 A for area up to 25 m 2, 30 A for up to 100 m 2).
In an alternating current (AC) electric power system, synchronization is the process of matching the frequency, phase and voltage of a generator or other source to an electrical grid in order to transfer power. If two unconnected segments of a grid are to be connected to each other, they cannot safely exchange AC power until they are synchronized.
A time switch (also called a timer switch, or simply timer) is a device that operates an electric switch controlled by a timer. Intermatic introduced its first time switch in 1945, which was used for "electric signs, store window lighting, apartment hall lights, stokers, and oil and gas burners." A consumer version was added in 1952.
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Special wiring rules apply to wet or corrosive locations, [13] and to locations which present an explosion hazard. [14] Wiring materials for use in the United States must generally be made and tested to product standards set by NEMA and Underwriters Laboratories (UL) and must bear approval marks such as those set by UL.
In 1948, Toro acquired Whirlwind Corp. and introduced a bagging system to rotary mowers. [8] It created its first snowblower in 1951, and in 1956 was the first lawn and garden manufacturer to advertise on television. [9] Toro purchased an irrigation equipment manufacturer in 1962 and entered the underground irrigation business. [9]