An operating system for a window covering includes at least one spring motor, at least one variable force brake, and at least one lift spool assembly operatively coupled to a panel for raising and lowering a panel. An effective shaft is operatively coupled to and synchronizes the spring motor, the variable force brake, and the lift spool. The variable force brake comprises a one-way clutch operatively coupled to the shaft. A brake member is operatively engaged with the one-way clutch to apply a brake force to the one-way clutch when the shaft is rotated. The magnitude of the brake force applied to the one-way clutch is determined by the rotational position of the shaft.