Vents RS-...-TA is a single phase fan speed controller designed for use in ventilation and air conditioning systems. It can be used to control the speed of fans with motors rated for 230V/50Hz and a maximum current draw of 1.5A, 3.0A, 5.0A, or 10.0A depending on the model chosen. The controller uses a TRIAC to vary the voltage supplied to the motor, allowing for smooth and precise adjustment of the fan speed. It has an On/Off button and accepts a 0-10V or 4-20mA control signal from an external source. The minimum and maximum fan speeds are adjustable using potentiometers on the controller.