Fans, motorized dampers, control valves and many other devices in your ventilation project require an analogue control signal to regulate between setpoints. This can be achieved by the use of switches, whether these are passive control switches and active control switches. Passive control switches are designed to manually adjust the speed of pole switching induction motors while Active control switches can be used to manually generate a 0-10 VDC signal in 3 or 4 steps.