Abstract: A multipurpose electric dryer including a housing covered with a front cover, a blast fan installed in the housing and having an air output port coupled with a fully clad electric positive-temperature-coefficient heater and connected to a first air hole and a second air hole on the front cover, a sliding hanger moved in a vertical sliding way on the front cover, a hot air hose having one end fixedly connected to the second air hole and an opposite end coupled with an airflow nozzle, a shutter linked to the sliding hanger and moved to alternatively open the air holes, a spring fastened to the front cover to pull the shutter away from the second air hole, wherein when the air-flow nozzle is hung on the sliding hanger, the sliding hanger is downward to pull the shutter rightward, causing the shutter to open the first air hole and close said second air hole, permitting hot air be driven out of a front opening on the front cover for drying the hands; when the air-flow nozzle it removed from the sliding hanger, the

Abstract: A PTC semiconductor heating device includes: two half shells combinable for forming a housing of the semiconductor heating device, a plurality of linear arrays of PTC semiconductor heating elements parallelly mounted in the housing with each linear array containing a plurality of PTC semiconductor heating elements longitudinally disposed in a side-by-side linear arrangement in said housing and each linear array of PTC heating elements being sandwiched in between every two neighboring thermally and electrically conducting units respectively connected to two poles of a power source and longitudinally juxtapositionally mounted in the housing each thermally and electrically conducting unit including a corrugated fin plate formed with a plurality of continuous square waves and clamped by a pair of conducting plates, and a plurality of resilient embedding plates each embedding plate resiliently inserted in between every two neighboring thermally and electrically conducting units for firmly tensioning, packing and r

Abstract: A hair dryer includes a plurality of elongated positive-temperature-coefficient (PTC) semiconductor heating units disposed in transverse side-by-side spaced relation in a linear array in a central air flow passage of an elongated tubular duct connected to a discharge port of a casing having an air fan rotatably mounted in the casing for blowing air through the air flow passage of the duct, each PTC heating unit defining a longitudinal axis disposed perpendicular to a longitudinal axis of the air flow passage of the duct and a plurality of elongated spaced fins longitudinally juxtapositionally mounted on the PTC semiconductor heating unit transversely of the longitudinal axis of the PTC heating unit, whereby upon a powering of the PTC heating unit and the fan to heat air as blown by the fan, the heated air will be guided in the tubular duct by the plurality of elongaed spaced fins to produce laminar air streamflow helpful for smoothly setting and drying hair or the like.

Abstract: A plurality of positive-temperature-coefficient (PTC) semiconductors are longitudinally positioned in an elongated, finned, thermally and electrically conductive hollow casing having a socket at each end. A first plug connector of a power source seals one of the sockets and is electrically connected to the lower conducting surface of each PTC semiconductor through an electrically conductive plate electrically insulated from the casing by an electrically insulative plate. A second plug connector of the source electrically seals the other socket and is electrically the connected to the upper conducting surface of each PTC semiconductor through an upper portion of the electrically conductive casing, thereby providing an electric heater with the PTC semiconductors and plates fully clad by the casing for enhanced safety, increased efficiency, and more stable construction.