Efficient electricity conversion for harvesting energy from low voltage sources
AssigneeNational Research Council of Canada
InventorsHEPING DING, RYAN GRIFFIN
Life of this patent
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Abstract
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.
Claims25
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 transformer for converting the AC signal produced by the oscillator to a higher voltage AC signal;
- a voltage doubling full wave rectifier for converting the higher voltage AC signal to the higher voltage DC output;
- wherein the first relatively voltage sensitive and relatively low power transistor and the second relatively voltage insensitive and relatively high power transistor of the oscillator are such that the oscillator is initially turned on when the low voltage DC input is sufficiently high to start the oscillator initially using only the first relatively voltage sensitive and the relatively low power transistor, and the second relatively voltage insensitive and relatively high power transistor turns on when the voltage on a secondary side of the transformer exceeds the turn-on voltage of the second transistor.
(canceled)
A method of converting a low voltage DC input to a higher voltage DC output, the method comprising:
- producing an AC signal from the low voltage DC input using an oscillator comprising a first relatively voltage sensitive and relatively low power transistor and a second relatively voltage insensitive and relatively high power transistor, by starting up oscillation of the oscillator when the low voltage DC input is sufficiently high to start the oscillator initially using only the first relatively voltage sensitive and relatively low power transistor, and turning on the second relatively voltage insensitive and relatively high power transistor when the voltage on a secondary side of the transformer exceeds the turn-on voltage of the second transistor;
- converting the AC signal produced by the oscillator to a higher voltage AC signal with a transformer;
- voltage doubling full wave rectifying the higher voltage AC signal to produce the higher voltage DC output.
Dependencies are inferred from the claim text.