Portable battery-less noncontact temperature measurement system powered on-demand by human action

This paper presents an autonomous battery-less temperature measurement system powered on-demand by human action. The conversion between the human action and electrical energy is provided by an hand-held electromagnetic (EM) converter intentionally activated by the user. The AC voltage generated by the EM converter has time-varying amplitude and frequency and is rectified by a voltage doubler active rectifier circuit. The energy harvested is stored into multiple capacitors by the innovative Sequential Charging of Storage Capacitors (SCSC) technique. With a force of about 29.4 N over 2 cm applied to the EM converter, the power management circuit is able to extract an energy of 27.5 mJ and power the noncontact temperature measurement system for about 17 s.