Jointed head with temporary clamp for stirling machine
Granted: June 29, 2010
Patent Number:
7744133
A clamping apparatus for allowing pre-close-out access to the head of a Stirling machine and facilitating subsequent close-out welding of the head. The head is axially separable into removable and fixed portions that engage each other. Each portion has an annular flange extending radially outwardly at its engaging end, and each flange has an annular groove. O-rings are seated in the grooves. A temporary sealing ring surrounds and engages the O-rings. Clamping rings seat against axially…
Solar cell having doped semiconductor heterojunction contacts
Granted: June 15, 2010
Patent Number:
7737357
A silicon solar cell has doped amorphous silicon contacts formed on a tunnel silicon oxide layer on a surface of a silicon substrate. High temperature processing is unnecessary in fabricating the solar cell.
Solar cell having polymer heterojunction contacts
Granted: May 18, 2010
Patent Number:
7718888
A solar cell having backside contacts is economically fabricated through use of acceptor and donor polymers which are inkjet printed in interleaved patterns on the back surface as the carrier accepting electrodes of the solar cell. The polymers can be placed on a tunnel oxide on the surface of a semiconductor substrate, or the polymers can be in direct contact with the semiconductor substrate. Electrical patterns interconnecting the acceptor and donor polymer patterns can also be formed…
Misalignment tolerant connector
Granted: May 4, 2010
Patent Number:
7708578
An electrical connector having a plug assembly and a socket assembly is described. The plug assembly includes a plug body and an outer barrel with an inner conductive receptacle electrically coupled to a first conductor in the plug body. The socket assembly includes a socket body movably held within an outer housing by a positioning ring, the socket body having a socket barrel with a second conductor fixed therein to be received in the conductive receptacle of the plug assembly.
Solar cell having silicon nano-particle emitter
Granted: April 27, 2010
Patent Number:
7705237
A silicon solar cell having a silicon substrate includes p-type and n-type emitters on a surface of the substrate, the emitters being doped nano-particles of silicon. To reduce high interface recombination at the substrate surface, the nano-particle emitters are preferably formed over a thin interfacial tunnel oxide layer on the surface of the substrate.
Hybrid electrical power source combining stirling engine driven alternator with supplementing electrical energy storage
Granted: April 20, 2010
Patent Number:
7701075
An electrical power source including a free-piston Stirling engine driving an alternator to supply power through a bus to a user load and controlled by an engine/alternator controller. A bidirectional DC/DC converter is connected between a battery and the bus. The stroke of the engine piston is modulated between a maximum and a minimum stroke to maintain the bus voltage at a design nominal bus voltage (V1), and charge the battery if it is not charged, when and so long as the bus voltage…
Connection of a free-piston stirling machine and a load or prime mover permitting differing amplitudes of reciprocation
Granted: March 30, 2010
Patent Number:
7685818
The reciprocatable power piston of a free-piston Stirling machine is drivingly linked to a reciprocatable component body of an associated apparatus by at least one spring with no rigid connection linking the piston to the component body. The spring drive linkage allows the power piston and the reciprocatable component body of the associated apparatus to reciprocate at different amplitudes of oscillation. Therefore, the Stirling machine and the associated apparatus can be optimized at…
Protection layer for fabricating a solar cell
Granted: March 2, 2010
Patent Number:
7670638
A method for fabricating a solar cell is described. The method includes first providing, in a process chamber, a substrate having a light-receiving surface. An anti-reflective coating (ARC) layer is then formed, in the process chamber, above the light-receiving surface of the substrate. Finally, without removing the substrate from the process chamber, a protection layer is formed above the ARC layer.
Back side contact solar cell with doped polysilicon regions
Granted: December 15, 2009
Patent Number:
7633006
In one embodiment, a back side contact solar cell includes a tunnel oxide layer formed on a back side of a substrate. A polysilicon layer is formed on the tunnel oxide layer, and dopant sources are formed on the polysilicon layer. Dopants from the dopant sources are diffused into the polysilicon layer to form p-type and n-type regions therein. The p-type and n-type regions form p-n junctions that, among other advantages, allow for relatively high conversion efficiency.
Electronic controller matching engine power to alternator power and maintaining engine frequency for a free-piston stirling engine driving a linear alternator
Granted: December 15, 2009
Patent Number:
7633173
A feedback control method and circuit for inclusion in a control system of an electrical power generating source that comprises a free piston Stirling engine driving a linear alternator. An instantaneous value of a variable, Vinternal, is continuously derived from other sensed and computed parameters and used in a negative feedback control loop of the control system to control engine piston stroke in order to maintain the power produced by the engine equal to the power transferred from…
Method for enabling monitoring of power consumption
Granted: November 24, 2009
Patent Number:
7622912
Power consumption at a site is monitored. An electrical load is connected to a power source by an electrical conductor. A fuel-less energy producing device is electrically connected to a junction along the electrical conductor. A current sensor is electromagnetically coupled to the electrical conductor at a sensing position between the power source and the junction to create a current sensor signal. Sensed current and voltage signals are produced from the current sensor signal. A sensed…
Multi-piece piston for a free piston machine
Granted: October 13, 2009
Patent Number:
7600464
The concentricity and coaxiality of a central bore through a piston for a free piston Stirling machine is improved with a piston that has a sleeve with a core constructed from at least two, separate, axially-engaging core components sealed within the sleeve. During fabrication, a central bore is machined through each of the core components. The piston is assembled by heating the sleeve and cooling the core components, inserting the core components into the sleeve and then allowing the…
Modular shade system with solar tracking panels
Granted: July 7, 2009
Patent Number:
7557292
A modular shade system with solar tracking panels includes a series of generally North-South oriented, spaced apart torque tubes, each torque tube having an axis, a series of panels mounted to at least some of the torque tubes to create spaced-apart rows of panels along the torque tubes, at least some of the panels being solar collector panels. The system also includes a shade structure, positioned at a selected location between selected ones of the torque tubes and above the support…
Tracking solar collector assembly
Granted: June 30, 2009
Patent Number:
7554030
A tracking solar collector assembly includes Southside supports, North side supports and support structures. Each support structure has pivotal support points defining a tilt axis and supports at least one solar collector. First support points of first and second support structures are pivotally connected to first and second Southside supports. A second support point of the first support structure is pivotally connected to first and second North side supports. A second support point of…
Preventing harmful polarization of solar cells
Granted: June 30, 2009
Patent Number:
7554031
In one embodiment, harmful solar cell polarization is prevented or minimized by providing a conductive path that bleeds charge from a front side of a solar cell to the bulk of a wafer. The conductive path may include patterned holes in a dielectric passivation layer, a conductive anti-reflective coating, or layers of conductive material formed on the top or bottom surface of an anti-reflective coating, for example. Harmful solar cell polarization may also be prevented by biasing a region…
Misalignment tolerant connector
Granted: May 12, 2009
Patent Number:
7530830
An electrical connector having a plug assembly and a socket assembly is described. The plug assembly includes a plug body and an outer barrel with an inner conductive receptacle electrically coupled to a first conductor in the plug body. The socket assembly includes a socket body movably held within an outer housing by a positioning ring, the socket body having a socket barrel with a second conductor fixed therein to be received in the conductive receptacle of the plug assembly. The plug…
Controller computing a virtual tuning capacitor for controlling a free-piston stirling engine driving a linear alternator
Granted: March 31, 2009
Patent Number:
7511459
A feedback control circuit and method for a control system used to control an electrical power generating source that comprises a free piston Stirling engine driving a linear alternator. A switching mode rectifier connects the alternator winding to an output circuit that includes an electrical energy storage means and is controlled by a pulse width modulator that controls the rectifier switching duty cycle and phase. The control system controls the pulse width modulator. The improvement…
Support structure for tracking solar collectors
Granted: February 17, 2009
Patent Number:
D586737
Back side contact solar cell with doped polysilicon regions
Granted: December 23, 2008
Patent Number:
7468485
In one embodiment, a back side contact solar cell includes a tunnel oxide layer formed on a back side of a substrate. A polysilicon layer is formed on the tunnel oxide layer, and dopant sources are formed on the polysilicon layer. Dopants from the dopant sources are diffused into the polysilicon layer to form p-type and n-type regions therein. The p-type and n-type regions form p-n junctions that, among other advantages, allow for relatively high conversion efficiency.
System for centering a workpiece on the central axis of a cylindrical bore
Granted: December 2, 2008
Patent Number:
7458143
A system for precisely centering a workpiece within a cylindrical bore such that the center of the workpiece is coaxial with the central axis of the bore. An arbor is used within the cylindrical bore to sense and calculate the location of the central axis. The position of the workpiece is also sensed so that it can be aligned with the central axis. A computer system is used to perform the calculations and provide an indication of alignment of the workpiece and the central axis. The…
