Abstract: Methods and apparatus for making and sensing ice. Also, apparatus and methods for sensing the change of phase of a substance. In one embodiment, a fringe-effect capacitor is placed proximate to a substance, such as water, which is undergoing a phase change, such as the change of phase from the liquid state to the solid state. During this change, the dielectric constant of the substance changes, and thereby changes the electrical flux between conductors of the fringe-effect capacitor. Also, apparatus and methods as described above, and using a capacitor but not a fringe-effect capacitor.

Abstract: A heater for a fuel supply system including a carburetor and a manifold for an internal combustion engine, the heater including an electrically inert core and at least one PTC disposed within a cavity in the core, the PTC heater being disposed upon an electrically conductive stratum such as copper sheet and a graphite stratum disposed next adjacent the conductive stratum, the graphite stratum acting as a compressible heat transmitting gasket between the fuel heater and the carburetor whereby to heat the fuel and prevent icing.

Abstract: A fuel heater for vaporization of an alcohol fuel from a fuel line to an internal combustion engine for delivering vaporous fuel to a carburetor. The fuel heater includes a stack of generally planar foraminous PTC heaters that are arranged in a container having an insulated interior defining a fuel flow path having an inlet and an outlet and are separated from each other by generally flat ring-like conductive spacers with electrically conductive ears having conductor receiving holes therein. Alternate conductive spacers are disposed in two channels in a housing and connected to opposite sides of a power supply whereby said PTC heaters can raise the temperature of the incoming fuel and vaporize it. Alternative ears of the electrically conductive spacers are radially offset from each other whereby one row of ears is disposed in one channel and another row is disposed in the other channel.