| 摘要 |
A programmable system for controlling the cyclic intermittent operation of a device, such as a flowing gas well. The system comprises battery powered, solid state circuitry including a programmable memory, an up/down counter and a liquid crystal display for the contents of either the memory or the counter. Programming and control information is introduced into the system through a plurality of touch actuated membrane switches under control of logic circuitry. The memory is first programmed with the desired "on" time and "off" time with which the controlled device is to be cyclicly operated. Once started, the system loads the time for the selected starting condition into the counter, establishes that condition in the device and begins counting down toward zero. When zero is reached, the opposite condition is established in the device, and the time for the duration of that condition is loaded from the memory into the counter which begins the down counting cycle again. The display is used to program times into the memory and to continuously display the time remaining in a cycle.
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