Zero power startup circuit for vibrational energy harvesting

An energy harvesting system for preventing unwanted battery drain, comprising:

• a transducer operable to harvest energy and to output an electrical current based on the harvested energy;
• a capacitor operable to store a rectified voltage based on the electrical current provided by the transducer;
• a power converter;
• a power converter control line;
• a control switch operable to be in one of an open state and a closed state, the control switch comprising one of:
• a metal oxide semiconductor field effect transistor having a gate tied to rectified DC voltage from a rectifier and a source/drain, the source/drain configured to couple with a battery and the power converter;
• and an electromechanical relay having a terminal tied to the rectified DC voltage from the rectifier and another terminal coupled with one of ground and a bipolar junction transistor;
• a battery;
• and
• a control switch control line,
• wherein said control switch control line is arranged to provide a control voltage, based on the rectified voltage, to said control switch,
• wherein, when the control voltage is less than a threshold voltage, said control switch is in an open state, and
• wherein said power converter control line decouples from said power converter.

A method of using an energy harvesting system for preventing unwanted battery drain, the system comprising a transducer, a capacitor, a power converter, a power converter control line, a control switch operable in one of an open state and a closed state, a battery, and a control switch control line, said method comprising:

• harvesting, via the transducer, energy, thereby providing harvested energy;
• outputting, via the transducer, electrical current based on the harvested energy;
• storing, via the capacitor, a rectified voltage based on the electrical current;
• providing, via the control switch control line, a control voltage, based on the rectified voltage, to said control switch, providing the control switch comprising providing one of:
• a metal oxide semiconductor field effect transistor having a gate tied to rectified DC voltage from a rectifier and a source/drain, the source/drain configured to couple with a battery and the power converter;
• and an electromechanical relay having a terminal tied to the rectified DC voltage from the rectifier and another terminal coupled with one of ground and a bipolar junction transistor;
• when the control voltage is less than a predetermined threshold voltage, placing the control switch in an open state, wherein the power converter control line decouples from the power converter, and wherein the power converter deactivates;
• and
• when the control voltage is equal to or greater than then instantaneous threshold voltage, placing the control switch in a closed state, wherein the power converter control line couples with the power converter, wherein the power converter receives an operating signal from the battery, and wherein the power converter outputs converted energy, based on the control voltage, to the battery.