Abstract: Combination line/microphone input circuitry is provided that adapts to receive either an audio line input or a microphone input via a single dual-purpose compound plug or input. More particularly, a combination line/microphone input circuit is provided to accept two different types of audio signals, being audio line signals and microphone signals, via a single dual-purpose plug or single input, such that the audio input circuitry is controlled or switched to accept either the audio line input or the audio microphone input signals, appropriately attenuate, filter and/or such input signals as necessary, then provide the resulting signal to other audio circuitry. Embodiments of the invention include additional circuitry that helps protect external line signal producing electronics from receiving incorrectly activated phantom microphone voltage.

Abstract: A method and apparatus for forming three-dimensional objects by laser sintering that includes the use of dense phase pneumatic conveying to internally recycle overflow powder, and to thoroughly blend overflow, recovered and virgin powder to provide a consistent powder feed mix to a laser sintering machine. Overflow powder from the laser sintering machine is recovered and recycled back into the laser sintering machine for reuse. The approach results in a compact and reliable powder recycle system with complete blending and minimum attrition to the handled powder.

Abstract: A method and apparatus for forming three-dimensional objects by laser sintering that includes the use of dense phase pneumatic conveying to internally recycle overflow powder, and to thoroughly blend overflow, recovered and virgin powder to provide a consistent powder feed mix to a laser sintering machine. Overflow powder from the laser sintering machine is recovered and recycled back into the laser sintering machine for reuse. The approach results in a compact and reliable powder recycle system with complete blending and minimum attrition to the handled powder.