Abstract: A solar powered lighting system, and a method of controlling the system, the method including monitoring a voltage level of a solar panel in the solar powered lighting system, monitoring a voltage level of a battery in the solar powered lighting system, controlling the solar panel to charge the battery when the voltage level of the solar panel is above a predetermined charging threshold, controlling the battery to power one or more lights of the solar powered lighting system when the voltage level of the solar panel is below a predetermined charging threshold and the voltage level of the battery is above a predetermined operating threshold, and suspending powering of the one or more lights when the voltage level of the battery is below the predetermined operating threshold.

Abstract: An accelerometer is fabricated by forming a proofmass and at least one associated hinge in a silicon substrate by ion implantation and the formation of an oxide support layer below the proofmass, subsequently integrally bonding two complementary proofmass and substrate structures together, and then removing the oxide support layer to leave the proofmass supported by the hinge within the body of silicon material. The proofmass may be electrically connected to a lead extending through an etched recess in one of the substrates; and the proofmass may be electrically isolated or separated from the substrates by an oxide layer and by a change in conductivity type of the semiconductor material where the hinge is structurally mounted to the substrates.

Abstract: An accelerometer is fabricated by forming a proofmass and at least one associated hinge in a silicon substrate through a variety of a etching and bonding processes is disclosed. The processes entail ion implantation and formation of an oxide support layer below the proofmass, integrally bonding two complementary proofmass and substrate structures together, and then removing the oxide support layer to leave the proofmass supported by the hinge within the body of silicon material. The proofmass may be electrically connected to a lead extending through an etched recess in one of the substrates, and the proofmass may be electrically isolated or separated from the substrates by an oxide layer and by a change in conductivity type of the semiconductor material wherein the hinge is structurally mounted to the substrates. In a bond and etch back process, the wafer is processed, sawed in half, and then bonded together again wherein the complementary halves are joined to obtain the finished accelerometer.

Abstract: An accelerometer is fabricated by forming a proofmass and at least one associated hinge in a silicon substrate by ion implantation and the formation of an oxide support layer below the proofmass, subsequently integrally bonding two complementary proofmass and substrate structures together, and then removing the oxide support layer to leave the proofmass supported by the hinge within the body of silicon material. The proofmass may be electrically connected to a lead extending through an etched recess in one of the substrates; and the proofmass may be electrically isolated or separated from the substrates by an oxide layer and by a change in conductivity type of the semiconductor material where the hinge is structurally mounted to the substrates.

Abstract: A digital force balanced instrument such as an accelerometer that incorporates a directly digital electrostatic forcer with servo loop plates charged by a digital feedback loop is disclosed. The accelerometer has a proofmass electrode suspended in a cantilever configuration between electrodes on either side thereof, which proofmass is displaced upon acceleration. Each side electrode includes a plurality of electrostatic plates sized in binarily weighted multiples of area. An induced signal in the proofmass electrode is quantized via A/D converter in the feedback loop, which activates the appropriate number of plates to force the proofmass to an initial position.

Abstract: An accelerometer is fabricated by forming a proofmass and at least one associated hinge in a silicon substrate through a variety of a etching and bonding processes is disclosed. The processes entail ion implantation and formation of an oxide support layer below the proofmass, integrally bonding two complementary proofmass and substrate structures together, and then removing the oxide support layer to leave the proofmass supported by the hinge within the body of silicon material. The proofmass may be electrically connected to a lead extending through an etched recess in one of the substrates, and the proofmass may be electrically isolated or separated from the substrates by an oxide layer and by a change in conductivity type of the semiconductor material wherein the hinge is structurally mounted to the substrates. In a bond and etch back process, the wafer is processed, sawed in half, and then bonded together again wherein the complementary halves are joined to obtain the finished accelerometer.

Abstract: A sensing electrode on a glass layer of an anodically-bonded capacitive sensor has an interfacial barrier film containing a nitride compound between the electrode and the glass layer. In one embodiment, the capacitive sensor is an inertial sensor having a sensing element hingedly mounted to a frame which is anodically bonded to the glass layer. The sensing electrode is then located on a surface of the glass layer facing the sensing element. The sensing element and the frame are preferably made of silicon and the interfacial film is preferably silicon nitride.

Abstract: A force balanced instrument, such as an accelerometer, employs a pendulous mass having combined electrostatic pickoff and forcing plates on opposite sides thereof. The plates provide a constant attractive force in successive periods acting alternatively on opposing sides of the sensitive element. Force balance is achieved by controlling the duty cycle so that the difference in duration between each of the parts of a full cycle is a linear measure of acceleration. Voltage on each of the forcing plates is sensed independently immediately after each is charged with a fixed charging pulse which provides a fixed force level over the duration of the part cycle. The two successive voltage samples are stored, and the difference between them integrated to control the duty cycle of a pulse width modulator, which itself controls the duration of application of the alternately directed forces applied by the respective plates to the pendulous mass.

Abstract: A substrate is formed from a core substrate of flexible, low-temeprature co-fireable ceramic tape and an outer substrate of ceramic tape having apertures for receiving integrated circuits (ICs) therein. The substrate is heated the form a rigid body which then mounts the ICs. The rigid body and ICs are covered or at least partially covered with an insulating glass and heated to a temperature that fuses the glass but does not harm the ICs. The resulting structure hermetically seals the ICs in a single substrate that is insensitive to acceleration forces.

Abstract: A substrate is formed from a core substrate of flexible, low-temperature co-fireable ceramic tape and an outer substrate of ceramic tape having apertures for receiving integrated circuits (ICs) therein. The substrate is heated to form a rigid body which then mounts the ICs. The rigid body and ICs are covered or at least partially covered with an insulating glass and heated to a temperature that fuses the glass but does not harm to ICs. The resulting structure hermetically seals the ICs in a single substrate that is insensitive to acceleration forces.

Abstract: A miniature, solid state, cantilever beam accelerometer is constructed with an arrangement of strain sensing elements which provides for simpler temperature compensation, dual-axis acceleration measurement, and the capability of correcting for nonlinearity in a strain sensing element. Temperature compensation is facilitated by locating two strain sensing elements on the cantilever beam and two on the main body of the accelerometer and connecting the four elements in a Wheatstone bridge. Instead of a single bridge, two half bridges may be formed to allow for independent adjustment of each side of the Wheatstone bridge. Independent adjustment is also possible by using two full bridges with all strain sensing elements oriented in the same direction. If the elements of one bridge are oriented in an orthogonal direction, the accelerometer is capable of measuring both on-axis and off-axis accelerations.