so im putting together a 3 "cylinder" selenoid motor. it will have 3 selenoids acting as "pistons" the selenoids are 120 degrees apart from eachother on the crankshaft. the next step is designing the triggering circuitry. the selenoids operate on 24VDC and only draw a few hundred mA. im looking for input on the circuitry. i would like to make it adjustable as far as how long each coil is turned on when it is triggered. what would be the best triggering method? there are reed switches, hall effect sensors, and optical detectors. any help would be appreciated!