Voltage adapter for a battery-powered camera system

Abstract

A voltage adapter for a battery-powered camera, including a boost regulating circuit, which is positionable between a camera and a camera battery. The power adapter being in communication with the battery and an appliance (e.g., a camera, a light, etc.) such that a constant boosted voltage (e.g., greater than the output voltage of the battery) is supplied to the appliance as the battery discharges. In a preferred embodiment the power supply further includes a buck regulator to maintain the proper output voltage when the battery voltage is greater than the output voltage.

Description

BACKGROUND OF INVENTION The present invention relates to electronic power supplies. More particularly, but not by way of limitation, the present invention relates to a power supply which would provide a pre-determined voltage output from batteries, which themselves could vary in number, voltage or level of charge. As will become apparent from the discussion below, there is generally a need for a boost regulator for battery-operated devices whereby the output voltage will remain constant over substantially the entire discharge cycle of the battery. There are several areas where this is especially true such as battery operated lighting used in the motion picture and television industries and for certain battery operated, motorized devices. U.S. Pat. No. 6,246,184 issued to Salerno represents a step in the right direction. Salerno discloses a boost regulator for a conventional battery operated flashlight wherein, after the battery voltage falls 15-20%, the boost regulator kicks in t...

AI Technical Summary

Benefits of technology

In yet another preferred embodiment, the inventive DC-DC converter provides a regulated output higher than the expected battery voltage. It is well known in the art that to achieve a particular torque from a DC motor, there is an inverse relationship between voltage and current. By providing a substantial increase in the operating voltage of the motor, the motor can employ smaller wire, experience reduced brush wear, etc. In addition, the inventive power supply is configured to output a tightly regulated voltage over a broad range of input voltages. Unlike directly powering the motor from a battery, or group of batteries, when driven from the inventive device, the motor will operate with consistent performance until the battery is essentially completely discharged.

Problems solved by technology

While Salerno provides a marked improvement for conventional hand-held flashlights, the improvements are limited to devices where the initial battery voltage is the same as the lamp voltage.

Such lamps are inefficient, not daylight balanced, and somewhat fragile compared to alternative lamps.

While xenon flashlights do have boosting circuits, they presently do not allow connection to anything other than 12 volt batteries and the output voltage varies with input voltage.

This leaves an enormous untapped potential in the battery.

If a car battery, through a power supply, were used to power one of the larger fixtures, battery life would be objectionably short.

In addition, xenon lamps have a zener diode-like characteristic in that, when a xenon lamp is operating, even small changes in lamp voltage result in disproportionately large changes in current.

They are also very sensitive to over-current conditions, which can easily destroy the devices.

Initially these fixtures do an adequate job of illuminating, but as the batteries run down, the light intensity fades.

Photography can't be precisely practiced with slowly dimming light levels.

These systems are very inefficient and when the battery discharges even slightly, the circuit begins to dim because there is not enough voltage in the battery to make up for the regulator voltage drop as well as other losses.

One could include a larger number of batteries to provide more head room for the regulator, but the higher voltages would cause efficiencies to drop even lower due to increased heating of the regulator.

Also the size and weight of the batteries would become unmanageable.

In addition, there are numerous fields in which it is either difficult to match a battery voltage to the requirements of an appliance, or the appliance is intolerant of the diminishing voltage of a draining battery.

At that point there is an enormous potential of electricity left but unusable in these batteries.

Not only is this number of batteries an expensive proposition, the management of this number of batteries is time consuming, creates logistic nightmares and is otherwise just generally problematic.

Even in this situation, however, the battery voltage can lag during a high cycle use of the motor.

The down side of this is that companies often have to make similar and somewhat redundant versions of a particular product line to operate at these different voltages.

Added to that, these similar versions may be accidentally confused with one another and consequently connected to incorrect voltages that may destroy the motor or its controller.

These multiple-battery configurations also have the added problem of the weakest link.

It is well known in the art that the weakest cell may actually reverse charge during normal use, further lowering the voltage available to the motor.

As with a single battery, when a the collective charge of a series of batteries is discharged to the point where the motor's performance degrades, there is a great deal of energy left in the batteries that can not be tapped by existing techniques.

This problem can also be found in battery-operated tools such as drills, saws, sanders, and the like.

Well before the battery charge is fully exhausted, but after the voltage has dropped a few volts, the motors of such devices will not develop enough torque to make the tools usable.

The investment in batteries can dwarf the investment in the tool itself.

Images