Differential amplifier circuits for LDMOS-based amplifiers are disclosed. The differential amplifier circuits comprise a high resistivity substrate and separate DC and AC ground connections. Such amplifier circuits may not require thru-substrate vias for ground connection.

An amplifier circuit amplifies a signal for wireless transmission. A feedback circuit, including a capacitor, is coupled to the amplifier circuit. Components of the feedback circuit are selected based on a feedback factor such that an input impedance to the amplifier circuit has a same impedance characteristic as a feedback circuit impedance of the feedback circuit.

A method of operating a switched-mode power supply (SMPS) for supplying power to a load circuit, which draws a supply current that varies with an input signal to the load circuit is disclosed. The method comprises monitoring the input signal and controlling the amount of accumulated energy transferred for consumption by the load circuit, in use, in accordance with the input signal.

A semiconductor package device comprises a radio frequency power transistor having an output port operably coupled to a single de-coupling capacitance located within the semiconductor package device. The single de-coupling capacitance is arranged to provide both high frequency decoupling and low frequency decoupling of signals output from the radio frequency power transistor.

Systems and methods are provided for generating an amplitude modulation signal to a switchmode power amplifier. A DC to DC switch is configured to receive a DC input voltage and to provide a DC output voltage. A low dropout regulator is configured to provide the amplitude modulation signal according to a modulation control signal received by the low dropout regulator. A control circuit is configured to establish a nominal operating power level for the power amplifier via the amplitude modulation signal and to maintain a minimum voltage difference between the DC output voltage and the low dropout regulator output. A modulator control circuit is configured to provide the modulation control signal to the low dropout regulator. The modulator control circuit provides the transition from a high amplitude to a low amplitude and a transition from the low amplitude to the high amplitude at configurable first and second slopes, respectively.

Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.

A transceiver includes: a power amplifying circuit arranged to generate differential output signals during a transmitting mode of the transceiver; a balance-unbalance circuit arranged to convert the differential output signals into a single-ended output signal; a switchable matching circuit arranged to receive the single-ended output signal on a signal port of the transceiver during the transmitting mode, and to convert a single-ended receiving signal on the signal port into a single-ended input signal during a receiving mode of the transceiver; and a low-noise amplifying circuit arranged to convert the single-ended input signal into a low-noise input signal during the receiving mode. The power amplifying circuit, the Balun, the switchable matching circuit, and the low-noise amplifying circuit are configured as a single chip.

Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different.

A voltage converter can be switched among two or more modes to produce an output voltage tracking a reference voltage that can be of an intermediate level between discrete levels corresponding to the modes. One or more voltages generated from a power supply voltage, such as a battery voltage, can be compared with the reference voltage to determine whether to adjust the mode. The reference voltage can be independent of the power supply voltage.

An automatic gain control device includes: a variable gain adjusting unit, for adjusting an input signal by a variable gain and outputting an adjustment result; an analog-digital converting unit, for performing analog-digital conversion on the adjustment result to obtain an analog-digital conversion result; and a gain determining unit, for determining a distribution status over a predetermined period of time of a maximum or a minimum of the analog-digital conversion result, comparing the distribution status with a first distribution condition, and if the distribution status meets the first distribution condition, then keeping the variable gain unchanged, otherwise changing the variable gain and determining newly a distribution status until the newly determined distribution status meets a second distribution condition which is at least as strict as the first distribution condition.

A machining system that includes an ultrasonic machining assembly, wherein the ultrasonic machining assembly further includes a machining tool; a collet adapted to receive the machining tool; and an ultrasonic transducer, wherein the ultrasonic transducer is operative to transmit acoustical vibrations to the machining tool; and a machining apparatus, wherein the machining apparatus is adapted to receive and secure the ultrasonic machining assembly, and wherein the machining apparatus is operative to transmit torque to the machining tool by applying rotary motion to the ultrasonic machining assembly.

Embodiments of the present invention generally provide chamber components with enhanced thermal properties and methods of enhancing thermal properties of chamber components including bonding materials. One embodiment of the present invention provides a method for fabricating a composite structure. The method includes applying a bonding material to a first component, and converting the bonding material applied to the first component to an enhanced bonding layer by heating the bonding material to outgas volatile species from the bonding material. The outgassed volatile species accumulates to at least 0.05% in mass of the bonding material. The method further includes contacting a second component and the enhanced bonding layer to join the first and second components.

An internal adapter for use in torque-limiting handles for interchangeable orthopedic tools contains a slidable collar component, house component, retaining ring, spring, driver component, cover and cam which engages a torque-limiting mechanism. A plurality of securing ball mechanisms releasably secure an orthopedic tool in the adapter, while a configuration of chamfered surfaces centrally stabilize the tool. A plurality of guiding chamfers located in a driver component rotationally secures the orthopedic tool.

A workholder to hold a workpiece, including a main body partially defining a fluid chamber, and a bladder carried by the main body with an interference fit, further defining the fluid chamber, and composed of an 80 to 100 durometer Shore A scale hardness polymer of a 12:1 to 18:1 diameter-to-wall-thickness ratio. Annular seals may further define the fluid chamber, and are disposed radially between the bladder and main body and axially adjacent the fluid chamber, and are composed of a 60 to 80 durometer Shore A scale hardness polymer. A collet is carried and driven by the bladder for gripping engagement with the workpiece.

A clamping unit (1) for machine tools (2) with a housing (11) connected in a rotationally fixed arrangement with a machine spindle, (5) and a screw drive (13) that interacts with a draw rod (6) such that rotational movements are converted into translational movements, the housing (11) being provided with an output element by which rotational movements are transmitted to an actuator (21). The housing (11) has an input element in a rotating mounting, with the actuator (21) acting on the input element, and the input element (29) is in driving connection with a shaft (14) by means of intermediate elements (31), whereby to direct rotational movements of the machine spindle (5) via the clamping unit (1), and for adjustment movements of differently configured clamping devices, to be converted into axial adjustment movements and transmitted directly onto the draw rod (6). No complicated electrical control devices and programs are required for adjusting and adapting a power chuck (3) linked to the draw rod (3) to different operating conditions.

A multi-spindle machining machine with a tool changing mechanism contains a base; a carrier including a seat to move in Z axis, a rotary shaft fixed on the seat laterally to drive the seat to rotate in A axis, and a fixing holder coupled to an end portion of the rotary shaft to fix a work piece; a tool changing mechanism including a mount mounted to the rotary shaft to rotate with the rotary shaft and a monitor fixed on the seat to measure a length of the tool clamped on a driving spindle, and including a plurality of slots to receive the tools respectively; a working head moving above the carrier and the tool changing mechanism in X and Y axes and including the driving spindle mounted on a lower end thereof to rotate axially, and the lower end of the driving spindle allowing to engage and disengage the tool.

The present invention relates to an apparatus and method for positioning and pressing surgical needle blanks. The apparatus includes a needle blank transferring system which transfers needle blanks between a gripping position and a pressing position. A side press system presses a portion of the needle blank when the blank is in the pressing position, and a gripping member is provided to hold the needle blank at least during the transfer and press operations of the apparatus. The method according to the present invention includes inserting a needle blank into a needle blank gripping member at a gripping position, transferring the needle blank between the gripping position and a pressing position, and pressing a side portion of a body portion of the needle blank with pressing dies.

A steel pin is disclosed of a type to be forcibly driven into a steel substrate by using a powder-actuated tool. The steel pin has a substantially cylindrical shank, and a substantially sharp point which extends from one end of the substantially cylindrical shank, which conforms substantially to a tangent or secant ogive except for a substantially spherical tip having a radius in the range of approximately 0.015 inch (approximately 3.75 millimeters) to approximately 0.03 inch (approximately 7.5 millimeters), which has substantially true concentricity, which has surface-texture irregularities with a roughness-height index value not greater than approximately 30 microinches (approximately 0.76 micrometers), and which appears to be substantially free of other surface imperfections when viewed under 60× magnification. Optimally, the ogive is a tangent ogive with an ogive radius approximately ten times the shank diameter and with an ogive length approximately twice the shank diameter, and the tip radius is approximately 0.1 times the shank diameter. The substantially cylindrical shank is joined to the substantially sharp point at a transition having a substantially smooth, continuously curved surface, and which is knurled near the transition. The steel pin is made by deforming a length of steel wire, as by forging or swaging, so as to form the steel pin.

A method and an apparatus is disclosed for forming a one-piece introducer needle having a member portion and a needle portion by introducing a photoresist on a substrate. The temperature of the substrate is increased and then decreased. A photomask is deposited onto a substrate.

A radial piston pump has a plurality of cylinders within which pistons reciprocally move. Each cylinder is connected to a first port by an inlet passage that has an inlet check valve, and is connected to a second port by an outlet passage that has an outlet check valve. A throttling plate extends across the inlet passages and has a separate aperture associated with each inlet passage. Rotation of the throttling plate varies the degree of alignment of each aperture with the associated inlet passage, thereby forming variable orifices for altering displacement of the pump. Uniquely shaped apertures specifically affect the rate at which the variable orifices close with throttle plate movement, so that the closure rate decreases with increased closure of the variable orifices.

A method of actuating an assembly of a transmission, with which are associated a plurality of actuators with whose help the assembly can in principle be actuated, such that out of the actuators available in principle for actuation, a control unit selects at least one actuator for the actual actuation and activates the selected actuator with an output signal in such manner that a status parameter of the actuated assembly corresponds to or follows a control-side nominal value, such that out of the actuators available in principle for actuating the assembly, the control unit selects at least one actuator for the actual actuation of the assembly in such manner that, for all the actuators available in principle for actuating the assembly over the operating life of the transmission, the extent of their utilization is approximately uniform.

Method of indicating the position of a hydraulically actuated armature, comprising an adjust cylinder for actuating the armature, connected by at least one pressure medium line to an adjustment valve through which the pressure medium line can be switched between pressure-causing forward flow and pressure-less backward flow, wherein the flow through the pressure medium line is converted into a number of electric pulses and the number of pulses reflecting the flow is processed in a program in an indicator unit such that the number of pulses occurring in a predetermined adjustment travel when the flow in the pressure medium line is pressure-less is calculated as being the same adjustment travel as when the pressure medium line is switched to be the pressure line.

The invention relates to a method for constructing a gas-filled double-acting hydraulic cylinder (1) with gas spring action, comprising: —a cylinder sleeve (3) with a cylinder bottom (3a) and cylinder head (3b) —a piston/piston rod assembly (5) a hydraulic fluid seal on the piston (9) —a connection for the head-side chamber (13) to a hydraulic line; —a connection for the bottom-side chamber (15) to a hydraulic line, —a gland (20) with a bore, the gland being attached between the cylinder bottom (3a) and the piston (9), the piston rod (7) extending over the entire stroke of the piston rod through the bore, wherein the gland comprises two seals —(25), one for providing a seal with the cylinder sleeve (3) and one for providing a seal with the piston rod.

A system comprises a first piston comprising a first piston shaft and a first drive pin. A first piston cylinder comprises a first body and a first groove, wherein the first groove defines a first aperture, the first aperture oriented axially along the first body and configured to receive the first drive pin. The first body encloses the first piston and allows the first piston to travel axially within the first piston cylinder. A drive shaft comprises an axis, a drive groove, and a surface, wherein the drive groove forms a continuous channel along the surface and receives the first drive pin. In one embodiment, a first distribution wheel comprises a first face, a second face, a first inlet aperture, and a first outlet aperture. The first distribution wheel couples to the first piston cylinder and to the drive shaft at a first end of the drive shaft, and rotates axially with the drive shaft along the axis of the drive shaft. The first inlet aperture allows hydraulic fluid to pass through the first face and the second face and the first outlet aperture defines a groove on the second face.

The invention relates to an energy-efficient apparatus driven by compressed air and equipped with a dual piston function for tensioning, or clamping, or centering, or punching, or welding, or clinching, for use in body construction in the automotive industry. The apparatus is driven by a pressurized fluid, in particular by compressed air. It is shown how a significant amount of operating costs can be saved while, at the same time, conserving the environment and consuming a low amount of pressurized fluid, in particular compressed air. In addition, the pivoting angle of a toggle joint assembly and thus of an apparatus connected thereto, for example, a tensioning arm of a toggle tensioning apparatus, can be continuously adjusted in both directions while, at the same time, adjusting a sampling device using sensors, for example, microswitches, or inductive switches, or pneumatic switches, or limit switches.

An apparatus can include a pressure vessel that defines an interior region that can contain a liquid and/or a gas. A piston is movably disposed within the interior region of the pressure vessel. A divider is fixedly disposed within the interior region of the pressure vessel and divides the interior region into a first interior region on a first side of the divider and a second interior region on a second, opposite side of the divider. The piston is movable between a first position in which fluid having a first pressure is disposed within the first interior region and the first interior region has a volume less than a volume of the second interior region, and a second position in which fluid having a second pressure is disposed within the second interior region and the second interior region has a volume less than a volume of the first interior region.

A servomechanism has a jet pipe mounted by a flexure pivot driven by an electromagnet to control the position of the jet pipe. A fixed seal tube surrounds the armature and keeps the coil isolated and dry. The flexure pivot has two parts that can move with respect to one another. The jet pipe can be fixed with respect to one part and movable with respect to the other such that when the electromagnet armature moves pivotal motion is imparted to the jet pipe. A multi-port jet receiver receives media from the jet pipe in different orifices dependent upon armature position. That in turn can extend or retract an actuator, such as a piston, depending upon which receiver orifice receives greater pressure. A feedback mechanism can link the actuator to the jet pipe to provide feedback input used to improve the accuracy of the device.

A radial thermal engine with an improved valve system is disclosed herein comprising intake and exhaust port valve assemblies fluidly connected to respective intake and exhaust ports contained within a cylinder head assembly. Each intake and each exhaust port valve assembly comprises at least one rotatable port cover having spaced apart openings which are periodically alignable to the intake and exhaust ports, respectively.

This disclosure provides for pressure limiting a hydraulic system to a desired pressure value by a particular circuit by controlling and closing the compensator when the desired pressure setting is achieved. Closing the compensator will reduced the pressure head and flow in the circuit resulting in improved efficiency. One illustrated embodiment of the disclosure provides a relief valve in the pilot signal for a compensator. The method relates to limiting the pressure on an open side of the compensator, such that the pressure on the other side closes the compensator thereby limiting the pressure and also flow in the hydraulic circuit. In other words, the pressure on the open side is limited by the relief valve. Thus, the pressure on the other side increases thereby regulating the flow and pressure through the compensator. In another embodiment of the disclosure, instead of reducing the pressure on the open side, the pressure on the closed side is increased, thereby controlling the flow and pressure of the hydraulic circuit. The pressure can be increased by a pump or any other suitable mode.

A pump assembly having an air motor includes a valve connected to a motive fluid inlet of the air motor. The valve shifts between a first position, in which a flow of motive fluid is directed into a pilot port, through a two way pilot conduit and into a pilot chamber portion, and a second position, in which the flow of motive fluid is inhibited from flowing into the pilot port through the two way pilot conduit and into the pilot chamber portion, and in which fluid in the pilot chamber portion flows out through the two way pilot conduit and is directed by the valve to exhaust. The valve is connected to a programmable logic controller, so that the valve is shifted between the first position and the second position in response to the programmable logic controller.

Valve control device includes a body with a longitudinal axis, a control member housed at least partially in the body in a bottom portion along the longitudinal axis, a piston movable along the longitudinal axis and housed in a portion of the body forming with the piston a control chamber of the piston, an element movable in rotation with respect to the longitudinal axis on a top portion of the body, and sealing means between the movable element and the control chamber in the area of the connection port and/or of the passage.

In a swash plate type variable capacity compressor that changes a stroke of a piston by controlling the pressure of a crank chamber (6), lubrication oil contained in refrigerant gas is maximally prevented from being circulated outside the compressor. Some of discharged refrigerant gas in a discharge chamber (22) flows into the crank chamber (6) through a communication passage (25) (25a and 25b) and a control valve (27), while some of the discharged refrigerant gas flows out to a suction chamber (21) from the crank chamber (6) through a second communication passage (26) and an orifice (28), and the pressure of the crank chamber (6) is controlled through a balance between an inflow amount and an outflow amount. Oil storage chamber (30) extends downstream of the control valve (27) on the first communication passage (25) to separate oil and store the separated oil. Oil return passage (31) returns the oil stored in the oil storage chamber (30) to the crank chamber (6).

A brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type having a brake booster. In order to provide a brake actuating unit for actuating a motor vehicle braking system of the “brake-by-wire” type, which on the one hand fulfills the statutory requirements care and which on the other hand is inexpensive to produce, it is proposed according to aspects of the invention, that the brake booster be provided as a travel-controlled brake booster, so that when not in the “brake-by-wire” operating mode the brake pedal is decoupled from feedback forces of the brake actuating unit, and the return force is simulated by the pedal travel simulator even when not in the “brake-by-wire” operating mode.

In a reciprocating piston compressor with delivery rate control, the electromagnetic actuating device (3) of the valve lifter (2) has a separate positioning drive (10) for adjusting the working stroke range of the magnetic actuator (5) used, whereby this can be chosen to be small and highly dynamic and only low power losses occur.

An assembly of valve sections includes an inlet section, an outlet section, a working section, and a working section. The working section is a conventional pressure compensated working section. The working section includes a directional control valve, a pressure compensator valve, and a pressure limiter valve. The valves are of integral construction, such that each is an essential part to complete the other. The pressure compensator valve includes a pressure compensator spool movable between an opened position and a closed position in response to a pressure differential across the spool. The pressure limiter valve includes a pressure limiter spool that moves to an open position to change the pressure differential and close the pressure compensator valve when a selected limit pressure is reached.

A volume booster for a fluid flow control device comprises a supply path for supplying a fluid boost to facilitate actuation of an actuator in a first direction, and an exhaust path for enabling controlled exhaust to facilitate actuation of the actuator in a second direction. The supply path defines a supply resistance that is set by the geometry of a supply trim component. The exhaust path includes an exhaust resistance that is set by the geometry of an exhaust trim component. The supply and exhaust trim components are independently removable and replaceable with replacement components to customize the exhaust and supply resistances, and therefore, the exhaust and supply capacities for specific applications.

A thin film of a low-thermionic-work-function material is maintained on the cathode of a device for producing a high-current, low-pressure gas discharge by means of sputter deposition from an auxiliary electrode. The auxiliary electrode includes a surface with a low-work-function material, such as thorium, uranium, plutonium or one of the rare earth elements, facing the cathode but at a disposition and electrical potential so as to extract ions from the gas discharge and sputter the low-work-function material onto the cathode. By continuously replenishing the cathode film, high thermionic emissions and ion plasmas can be realized and maintained over extended operating periods.

An improved control system for controlling the position of an upper electrode in a carbon arc lamp. The system has a pulley with a line thereover, and a solenoid core is attached to one end of the line and is movable vertically in a solenoid coil connected in the circuit for supplying discharge current to the electrodes, and a control rod clutch is connected to the other end of the line which normally grasps and holds an electrode control rod on the lower end of which is mounted the upper electrode of the lamp. A balancing weight is provided on the core to balance the weight of the control rod clutch and electrode and a shield is provided around the solenoid coil to shield the arc between the electrodes from the magnetic field of the solenoid coil.

An electrical discharge machine with automatically replaceable electrodes. The machine includes an electrode holder with a clamp operable to alternately receive and release an electrode, an electrode cartridge containing a plurality of stacked electrodes and a shuttle movable toward and away from the electrode holder. When the shuttle is moved toward the electrode holder, it removes an electrode from the cartridge and moves it into alignment with the electrode holder.

Graphite and/or carbon surfaces are coated with a titanium nitride coating by exposing the substrate to electric arc thermal spray process wherein titanium wire as the source of titanium and nitrogen is used as the propelling (atomizing) gas.

An auxiliary lighting system for a high-intensity discharge lamp. In one embodiment, the auxiliary lighting system has an auxiliary light source, an HID lamp status circuit having an input for connection to a status signal representative of the operational state of a high-intensity discharge lamp wherein the HID lamp status circuit determines whether the status signal meets predetermined signal criteria, a switch circuit having a first state that effects application of a voltage source to the auxiliary light source, and a second state that isolates the voltage source from the auxiliary light source, and a control circuit responsive to the HID lamp status circuit for controlling the switch circuit. The control circuit has a first state when the HID lamp status circuit determines that the status signal meets the predetermined signal criteria and a second state when the HID lamp status circuit determines that the status signal does not meet the predetermined signal criteria. When the control circuit is in the first state, the control circuit outputs a control signal for input into the switch circuit that configures the switch circuit into the first state. When the control circuit is in the second state, the control circuit outputs a control signal for input into the switch circuit that configures the switch circuit into the second state.

An information handling system (IHS) employs a power fault protection circuit to protect the IHS from overvoltages which may occur on an information line from a power adapter to the IHS. The system includes a processor coupled to the protection circuit. The circuit is operative in a first mode to decouple an information line from the IHS in response to a disable command and operative in a second mode to decouple the information line from the IHS when a voltage in the information line exceeds a predetermined threshold voltage.

An analog-to-digital converter can use a variable sampling rate. By using a variable sampling rate analog-to-digital converter and an anti-aliasing filter lower sampling rates, and accordingly, generally lower power consumption may be achieved. For example, a lower sampling rate can be used when it is determined that no undesirable signals are present and a higher sampling period can be used when an undesirable signal is present. Determining the presence of an undesired signal can be based on signal-to-noise ratio, over-sampling, bit error rate, using a detector, etc. An undesirable signal can be any signal that is close in frequency to a signal of interest or a signal farther away in frequency that has a relatively high amplitude. Sampling rate can be varied in a binary fashion, stepwise, continuously, etc.

An analog front-end circuit includes an analog processing circuit, an A/D converter, a target register in which a lower limit target value of an input image signal is set, and a calculation circuit. The analog processing circuit includes an offset control circuit which performs offset control based on an offset control value set in an offset control register. The calculation circuit monitors the A/D-converted value in a lower limit value output period when the A/D-converted value corresponding to a lower limit value of an input range is output from the A/D converter, and sets the offset control value that causes the A/D-converted value to become closer to the lower limit target value set in the target register in the offset control register.

A power tool has an electric motor that includes a commutator, with which at least one commutator brush is acted upon with spring force via at least one commutator spring in the direction of a non-rotatable collector of the commutator. At least one auxiliary tool for adjusting the commutator spring is located on a component of the power tool.

The present invention relates to a method and apparatus for explicit filtering in ambiguous text entry. The invention provides embodiments including various explicit text entry methodologies, such as 2-key and long pressing. The invention also provides means for matching words in a database using build around methodology, stem locking methodology, word completion methodology, and n-gram searches.

There are provided an apparatus and a method for manufacturing a vitreous silica crucible which can prevent the deterioration of the inner surface property in the manufacturing process of a vitreous silica crucible. The apparatus includes a mold defining an outer shape of a vitreous silica crucible, and an arc discharge unit having electrodes and a power-supply unit, wherein each of the electrodes includes a tip end directed to the mold, the other end opposite to the tip end, and a bent portion provided between the tip end and the other end.

Apparatuses, methods and systems for lighting fixture determining its power usage and monitoring its operational health are disclosed. One embodiment includes a method of a lighting fixture determining its power usage. The method includes sensing, by an ambient light sensor, an intensity of light emitted from the lighting fixture, and estimating power usage of the lighting fixture based on the sensed intensity of light.

A line voltage control circuit for use with a multi-string LED drive system which provides a common line voltage for multiple LED strings that are connected to respective current sink circuits at respective junctions. An error amplifier receives the minimum junction voltage and a reference ‘desired junction voltage’ at respective inputs, and a voltage regulator outputs the line voltage in response to a voltage applied to a feedback input. A comparator toggles an output when the maximum junction voltage (Vmax) exceeds a reference limit (Vlimit). A multiplexer receives the error amplifier output and a fixed voltage at respective inputs and provides one of the signals to the regulator's feedback input in response to the comparator output. When Vmax>Vlimit, the fixed voltage is provided to the feedback input and the line voltage is reduced, thereby protecting low voltage current sinks from potentially damaging high voltages.

A sleigh for travel over a snow covered surface adapted to be disassembled or knocked down into a storage or transport position, from an operating position, is shown. Runners of the sleigh are pivotally connected to a floorboard along side edges thereof. The runners are locked into an operating position and may be unlocked to fold against a bottom surface of the floorboard in a stored position. An upper body including a seat is formed of multiple planar pieces which are dependently interlocked with each other for assembly and later disassembly. Means are provided for interlocking the runners to a hitching assembly to which a horse is conventionally harnessed.