This liquid nitrogen generator uses a Stirling-cycle cryocooler that was pulled from a cellular phone tower. It was used to cool a superconducting RF filter that aids cell communications. The cryocooler is able to pump enough heat away from its cold end that air will liquify and drip into a vacuum flask for storage.
Jeri's video at Maker Faire 2010: [ Ссылка ]
Blog post with more construction details: [ Ссылка ]
