National Research Council of Canada

Ryan Griffin

Heping Ding

Ye Tao

Neil Graddage

George Xiao

A DC-DC converter for converting a low voltage DC input to a higher voltage DC output, the DC-DC converter comprising: an oscillator comprising a first relatively voltage sensitive and relatively low power transistor and a second relatively voltage insensitive and relatively high power transistor, the oscillator producing an AC signal from the low voltage DC input; a first transformer for converting the AC signal produced by the oscillator to a higher voltage AC signal; an autonomous, synchronous voltage-doubling rectification circuit for converting the higher voltage AC signal to the higher voltage DC output, wherein the autonomous, synchronous voltage-doubling rectification circuit comprises a second transformer, a first shunt switch and a second shunt switch; and wherein current through the second transformer controls the synchronous rectification.

Synchronous rectification to improve efficiency of electricity conversion for harvesting energy from low voltage sources

An electrostatic concentrator for use in radon detection, comprising of a plastic sheet having conductive electrodes patterned onto the surface. The sheet is patterned and cut in such a way that it can be assembled into a three-dimensional shape (e.g. a cone), such that when a voltage is applied to the electrodes an electrostatic field is created for propelling radon progeny towards a sensor on which it can be detected.

Printed film electrostatic concentration for radon detection

A DC-DC converter and method are provided for converting a low voltage DC input to a higher voltage DC output. The DC-DC converter has an oscillator with a first relatively voltage sensitive and relatively low power transistor and a second relatively voltage insensitive and relatively high power transistor, the oscillator producing an AC signal from the low voltage DC input. The inclusion of the voltage sensitive transistor allows the oscillator to turn on at a relatively low voltage. The inclusion of the higher power transistor allows the oscillator to operate at a higher power once it turns on. The DC-DC converter can be used for converting energy harvested from low voltage sources.

Efficient electricity conversion for harvesting energy from low voltage sources

A voltage and current triggered switch that turns on when a voltage across the switch reaches a turn-on voltage and that turns off when a current through the switch drops below a holding current. The switch features a Zener diode having a breakdown voltage. The Zener diode is connected to set the turn-on voltage of the switch to be the breakdown voltage of the Zener diode. Also provided is a step-down DC-DC converter comprising such a switch. Also provided is a system that has a tribo-electricity source or a piezo-electricity source, the provided step-down DC-DC converter and a load connected to an output of the stepdown DC-DC converter.

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Ottawa, Canada

Ryan Griffin