摘要 |
<p>A control system and method for chemical injectors includes a controller which outputs multiple feed set point signals and associated driver signals, each set point signal defining a desired injection capacity for a chemical injector and the associated driver designation signal designating the injector to receive the set point signal. A driver assembly is associated with each injector. The driver assembly receives a capacity signal from the injector which defines the volumetric injection capacity of the injector, compares the capacity signal to the feed set point signal, and outputs a drive signal to adjust the volumetric injection capacity of the injector. An adjustment assembly is provided for receiving the drive signal and positioning a stop to limit the reciprocal motion of the piston of the injector, thereby adjusting the volumetric injection capacity of the injector. The injectors inject into a common carrier fluid, such as irrigation water, and the carrier fluid, through a carrier fluid flow operated valve, is also used to reciprocate the injector pistons. A disabling assembly is provided to disable the driver assemblies when the pistons of the injectors are forced against the stops.</p> |