Electric power conversion systems – Current conversion – Using semiconductor-type converter
Reexamination Certificate
1999-12-16
2001-09-18
Sterrett, Jeffrey (Department: 2838)
Electric power conversion systems
Current conversion
Using semiconductor-type converter
C307S048000
Reexamination Certificate
active
06292381
ABSTRACT:
The present invention generally relates to power supplies for battery operated devices, and more particularly to an AC power supply system which is adapted to supply DC power to battery operated devices.
It is common for power devices or tools such as drills, circular saws, sanders, etc., to be battery powered. If such devices are adapted to be battery driven, they necessarily have DC motors, and if they are connected to an AC power source, they must have an AC to DC converter to operate the devices. Many tools are designed to receive cordless power packs which lock directly onto the tools, and is desirable to have a corded AC to DC converter be sized so that it will also fit in the same compartment as the power pack.
A typical converter includes a power transformer device for converting AC power to DC power and supplying the converted DC power to the tool. The transformer contained in the converter tends to heat-up, particularly if there is a large load developed from the use of the tool. Increasing the size of the transformer can prevent or at least alleviate the over-heating problem, but there is a cost associated with the larger size and there are practical size constraints imposed by the compartment of the tool in which the converter is intended to fit. Also, a large transformer may be undesirable because the size and weight of the power supply may make it difficult to use the tool.
Accordingly, it is a primary objective of the present invention to provide an improved AC to DC power supply for powering DC devices and tools which is adapted to provide adequate DC power, but which is capable of supplying high power to meet an electrical load drawn by a tool for short time periods.
Another object of the present invention to provide such an improved AC to DC power supply which has a transformer with a predetermined power rating, the power supply being capable of supplementing the power supplied from the transformer to meet an electrical load drawn by a tool that cannot be supplied by the transformer alone.
A more detailed object of the present invention is to provide such an improved power supply that has a transformer with a predetermined power rating and a battery that can provide high current almost instantaneously to supplement the transformer output to meet short duration electrical loads that occur during operation of a tool or other device.
Another object of the present invention is to provide such an improved power supply that is adapted to simultaneously provide power to the tool and charge the battery when the battery is not supplying power to the tool.
Other objects and advantages will become apparent upon reading the following detailed description, in conjunction with the attached drawings, in which:
FIG. 1
is a block diagram of the present invention;
FIG. 2
is a detailed schematic diagram of the circuitry of
FIG. 1
; and,
FIG. 3
is a chart of the current vs. the voltage of the output of the present invention under various operating loads.
REFERENCES:
patent: 2675490 (1954-04-01), Portail
patent: 3257603 (1966-06-01), Laube
patent: 3267288 (1966-08-01), Maiden et al.
patent: 3599073 (1971-08-01), Wilson et al.
patent: 3950690 (1976-04-01), Campbell
patent: 4700122 (1987-10-01), Cimino et al.
patent: 4959766 (1990-09-01), Jain
patent: 5045086 (1991-09-01), Juergens
patent: 5150032 (1992-09-01), Ho
patent: 5243510 (1993-09-01), Cheney
patent: 5255175 (1993-10-01), Uchino
patent: 5422804 (1995-06-01), Clark
patent: 5568038 (1996-10-01), Tatsumi
patent: 5581449 (1996-12-01), Sridharan
patent: 5675486 (1997-10-01), Ishii
patent: 5933342 (1999-08-01), Callahan
patent: 6040640 (2000-03-01), Gehre et al.
Neumann Peter W.
Vassos Louis J.
Greer Burns & Crain Ltd.
S-B Power Tool Company
Sterrett Jeffrey
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