Red Lion Controls PRS10101Product Attribute Attribute Value Series PRS1 Series Voltage, Control 115 VAC Overview The PRS1 is a versatile, reliable and economical solution to most machine speed switching problems. It is not affected by overspeeding and will operate in either direction of rotation. The heart of the PRS1 is a solid state CMOS logic circuit, that continuously measures the elapsed time between successive trailing edges (negative going) of an incoming pulse train or