What is claimed is:
1. A constant voltage discharge device, comprising:
means for receiving electrical current at a first voltage level;
means for charging a capacitor to a second voltage level, higher than the first voltage level;
means for discharging the storage capacitor in response to a predetermined condition to generate an output current; and
means for decreasing the output voltage level.
2. The constant voltage discharge device of claim 1, wherein the means for receiving electrical current comprises an input node connected to a power supply.
3. The constant voltage discharge device of claim 1, wherein the means for charging a capacitor comprises a first DCDC voltage converter that receives an input current at a first voltage level and generates an output current at a second voltage level.
4. The constant voltage discharge device of claim 3, further comprising an electrical connection between the output of the first DCDC voltage converter and an input of the capacitor.
5. The constant voltage discharge device of claim 1, wherein the means for discharging the storage capacitor in response to a predetermined condition to generate an output current comprises a switch for connecting the storage capacitor to an output node.
6. The constant voltage discharge device of claim 1, wherein the means for discharging the storage capacitor in response to a predetermined condition comprises means for determining a voltage at the output node.
7. The constant voltage discharge device of claim 6, wherein the means for determining a voltage at the output node comprises a feedback in that samples the voltage between a first resistor connected to the output node and a second resistor connected to ground.
8. The constant voltage discharge device of claim 1, wherein the means for decreasing the voltage level of the output current comprises a second DCDC voltage converter.
9. A method for supplying a constant discharge voltage, comprising:
receiving an electrical current at a first voltage level;
charging a capacitor to a second voltage level, higher than the first voltage level;
discharging the storage capacitor in response to a predetermined condition to generate an output current; and
decreasing the output voltage level.
10. The method of claim 9, wherein charging a capacitor to a second voltage level, higher than the first voltage level comprises activating a first DCDC voltage converter having an input that receives an electrical current at a first voltage level and having an output connected to the capacitor.
11. The method of claim 10, further comprising deactivating the first DCDC voltage converter when the capacitor is charged to a predetermined voltage level.
12. The method of claim 9, wherein discharging the storage capacitor in response to a predetermined condition to generate an output current comprises detecting a drop in the output voltage.
13. The method of claim 9, wherein decreasing the voltage level of the output current comprises activating a second DCDC voltage converter having an input connected to the capacitor and an output that produces an electrical current at a voltage level less than the input.
14. A first circuit for supplying power to a second circuit, comprising:
a first DCDC voltage converter having an input connected to a power supply for receiving an electrical current at first voltage and converting the electrical current to a second voltage, greater than the first voltage;
a capacitor connected to an output of the first DCDC voltage converter for storing energy at the second voltage level; and
a second DCDC voltage converter having an input connected to the capacitor for discharging energy from the capacitor and generating an output having a voltage level less than the first voltage level.
15. The circuit of claim 14, wherein the first DCDC voltage converter comprises an input that monitors the voltage on the capacitor.
16. The circuit of claim 15, wherein the first DCDC voltage converter deactivates when the voltage on the capacitor exceeds a predetermined threshold.
17. The circuit of claim 14, wherein the second DCDC converter comprises an input that monitors the output voltage, and activates the second DCDC converter when the output voltage drops below a predetermined threshold.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A vehicle energy harvester comprising:
a subunit having an upper surface forming a roadway surface;
a vehicle activated treadle on the subunit, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface;
a generator that generates power in response to movement of the vehicle activated treadle; and
a vehicle speed detection device that detects a speed of a vehicle travelling over the roadway surface based on a speed of movement of the vehicle activated treadle.
2. The vehicle energy harvester of claim 1, wherein the vehicle speed detection device includes:
an infrared (IR) emitter;
an infrared (IR) detector, and
a rotating arm portion coupled to the vehicle activated treadle and moveable between the infrared (IR) emitter and the infrared (IR) detector during movement of the vehicle activated treadle.
3. The vehicle energy harvester of claim 2, wherein the rotating arm portion includes include one or more apertures through which an infrared beam emitted from the infrared (IR) emitter passes through the rotating arm portion and is detected by the infrared (IR) detector.
4. The vehicle energy harvester of claim 2, wherein the rotating arm portion includes two apertures through which an infrared beam emitted from the infrared (IR) emitter passes through the rotating arm portion and is detected by the infrared (IR) detector.
5. The vehicle energy harvester of claim 4, wherein the infrared beam emitted from the infrared (IR) emitter passes through each of the two apertures during movement of the rotating arm portion, a body portion of the rotating arm portion between the two apertures preventing the beam from being detected as the body portion moves between the infrared (IR) emitter and the infrared (IR) detector.
6. The vehicle energy harvester of claim 4, wherein the vehicle speed detection device calculates the speed of movement of the vehicle activated treadle based on a time between the infrared (IR) detector detecting the beam passing through a first aperture of the two apertures and the infrared (IR) detector detecting the beam passing through a second aperture of the two apertures.
7. The vehicle energy harvester of claim 1, wherein the subunit is an entry ramp of the roadway surface and the entry ramp includes the vehicle speed detection device,
the vehicle energy harvester further comprising:
a plurality of subunits each having an upper surface forming the roadway surface; and
a plurality of vehicle activated treadles on the plurality of subunits.
8. A vehicle energy harvester comprising:
a plurality of subunits each having an upper surface forming a roadway surface;
a vehicle activated treadle on at least one of the plurality of subunits, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface;
a generator that generates power in response to movement of the vehicle activated treadle; and
a vehicle speed detection device that detects a speed of a vehicle travelling over the roadway surface based on a speed of movement of the vehicle activated treadle.