Abstract: A mixing valve for mixing airstreams in an air distributing system including a housing having first and second air inlet passages therein for receiving respective airstreams of different characteristics, valve means cooperating with the first and second inlet passages for adjustably selecting the proportion of air received through the respective passages so as to obtain a mixture of the two airstreams from the mixing valve, and an actuator cooperating with the valve means for effecting adjustment of the same to obtain a desired mixture of the different airstreams from the mixing valve. The actuator includes a thermal motor having an axially movable shaft extending therefrom, a heater cooperating with the thermal motor for applying heat thereto to effect movement of the motor shaft toward an extended axial position, and linkage operably interconnecting the thermal motor and the valve means and being movable in response to axial movement of the motor shaft for effecting adjustment of the valve means.

Abstract: A gas smooth top range in which the burner beneath the glass ceramic top is of powered blue flame, rather than radiant, type. The burner in this and other possible environments is controlled by electric circuit means including a resistance igniter element having an appreciable energy output, electrically operated valve means in circuit with the igniter, and cycle control means for cyclically energizing the igniter and valve means at a rate that can be varied to regulate the heat output of the burner. Heat transfer structure is associated with the burner and arranged so that hot exhaust gases from the burner are effective to preheat the respective inflows of ambient air and fuel making up the mixture which is combusted.