Capacitive power supply for handheld device

1. A device comprising:

an electronic instrument having a minimum operating voltage; and

a capacitive power supply configured to deliver power to the electronic instrument, the capacitive power supply comprising:

at least one capacitor arranged and configured to store energy to power the electronic instrument;

a boost converter circuit electrically connected to receive power from the capacitor and arranged and configured to boost a voltage from the capacitor to a variable voltage level output greater than or equal to the minimum operating voltage when the voltage from the capacitor falls below the minimum operating voltage;

a boost regulator coupled to receive power from the at least one capacitor and operable to generate a substantially constant fixed voltage;

a variable control configured to receive input from a user; and

a programmable controller powered by the substantially constant fixed voltage and programmed to adjust the variable voltage level output from the boost converter based on the input received from the user.

2. The device of claim 1 , wherein the device is a handheld medical device, and wherein at least one capacitor is a primary energy storage device of the handheld medical device.

3. The device of claim 1 , wherein the capacitive power supply is battery-free.

4. The device of claim 1 , wherein the electronic instrument includes a light source selected from a bulb and a light emitting diode.

5. The device of claim 1 , wherein the at least one capacitor has a capacitance of greater than 100 F, a power density of greater than 1,000 W/kg, and an energy density in a range from about 1 Wh/kg to about 10 Wh/kg.

6. The device of claim 1 , wherein the minimum operating voltage is the minimum voltage required to power the electronic instrument for effective use by a healthcare provider during a patient encounter.

7. The device of claim 1 , wherein the device is a handheld medical device.

8. A power handle comprising:

a housing sized to be held in a hand, the housing including an interface arranged and configured to connect the power handle to an otoscope including a light generator, the interface including a mechanical interface and an electrical interface, the mechanical interface detachably connecting the housing to the otoscope, and the electrical interface configured to electrically connect the power handle to the light generator of the otoscope to provide power to the light; and

a capacitive power supply arranged within the housing and configured to deliver power to the electronic instrument, the capacitive power supply comprising:

a primary power storage device comprising a capacitor;

a boost converter operable to boost a voltage from the capacitor to a higher variable voltage and to deliver power at the higher variable voltage to the interface to supply power to the electronic instrument;

a boost regulator coupled to receive power from the capacitor and operable to generate a substantially constant fixed voltage;

a variable control configured to receive input from a user; and

a programmable controller powered by the substantially constant fixed voltage and programmed to adjust the higher variable voltage output from the boost converter based on the input received from the user.

9. The power handle of claim 8 , wherein the mechanical interface comprises screw threads.

10. The power handle of claim 8 , wherein the variable control is a rheostat.

11. The power handle of claim 8 , wherein the housing has a cross-sectional dimension of less than about 3 inches.

12. The power handle of claim 8 , further comprising an inductive charging circuit including at least one coil, the coil shaped and positioned to receive power from an external charging station, and the inductive charging circuit including electronics to deliver the power to the at least one capacitor to recharge the at least one capacitor.

13. The power handle of claim 8 , wherein the housing is sealed except at the interface.

14. A handheld medical device comprising:

a capacitive power supply comprising:

at least one capacitor that is a primary power storage device for the handheld medical device;

a boost converter circuit electrically connected to receive power from the at least one capacitor and arranged and configured to boost a voltage from the at least one capacitor to a variable voltage;

a boost regulator coupled to receive power from the at least one capacitor and operable to generate a substantially constant fixed voltage;

a variable control configured to receive input from a user; and

a programmable controller powered by the substantially constant fixed voltage and programmed to adjust the variable voltage level output from the boost converter circuit based on the input received from the user; and

a charging circuit configured to receive power from a charging station and deliver the power to the capacitor, wherein the charging circuit is operable to charge the capacitor from a depleted state to a charged state in less than five minutes.

15. The handheld medical device of claim 14 , wherein the charging circuit is operable to charge the capacitor from the depleted state to the charged state in less than one minute.

16. The handheld medical device of claim 14 , wherein the charging circuit includes electrical contacts to directly receive power from the charging station.

17. The handheld medical device of claim 16 , wherein the charging circuit includes a coil for inductive transfer of power from the charging station.

18. The handheld medical device of claim 14 , further comprising a status indicator visually indicating a charge status of the capacitor.