Connect the other end of the wire you cut (this is the wire that goes to the existing thermostat) to the points of the DPDT relay that connect to the moving points when the relay has no power applied to the coil.
Connect the other end of the wire you cut (this is the wire that goes to the existing thermostat) to the points of the DPDT relay that connect to the moving points when the relay has no power applied to the coil.
Build a Telephone Remote Control Thermostat
Build a Hydrometer
Build a Small Sheet Metal Brake
Build a Home Theater PC (HTPC)