of rotation from the predetermined position the maintenance and referencing of discrete positions by the position controller may be further enhanced when deployed with a stepper motor comprising the drive motor 221 the control assembly 200 may be powered by an integral power source 400 but in other embodiments may be powered by a central power source of the structure in which the system 10 is deployed the power source 400 can include a rechargeable battery 410 as well as a charging station 420 connected to the rechargeable battery 410 in at least one embodiment the charging station 420 may comprise a turbine 421 operatively connected to the battery and structured to be powered by the passage of fluid thereby as the turbine 421 rotates it will generate electricity to recharge the rechargeable battery 410 the system 10 may be further programmed to dispose the vent 100 in an open orientation upon reaching a predetermined voltage of the rechargeable battery 410 thusly programmed the system 10 can avoid completely depleting the rechargeable battery 410 due to the vent 100 remaining in a closed orientation and failing to allow fluid flow to operate the turbine 421 now generally referring to fig1 and 2 a user may desire to set the digital thermostat 310 to a.