Sequential Timers Solid State Sequential Controller is to operate the Pulse Jet Valves used on dust collector sequential timers in Delhi. Light emitting diodes ( LEDs ) provide visual indication of which pilot valve is being energized as well as “Powar On “ indication. The number of sequenced steps is adjustable from 2 through 10. Controls are provided t adjust the length of time between valves being energized ( Pulse Frequency ) and the length of time that the valve is energized ( Pulse Duration ). Silicon semiconductor components control all timing and logic functions. Sequential Timers are available in 10, 18 & 27 Channel.