摘要:
A lawn mower has a dual-tubular frame for shock absorption. The dual-tubular frame has two parallel, longitudinally-extending tubular structures with curved portions allowing for flexion. A seat bracket interconnects the tubular structures. An engine is mounted to the tubular structures rearward of the seat bracket.
摘要:
To achieve a particular price point and/or to utilize a particular engine, riding lawn mowers may be configured with reduced size, weight, and/or power requirements, in order. A riding lawn mower may comprise a cutting deck coupled to a cutting blade, and an internal combustion engine having a displacement of less than 225 cubic centimeters. The internal combustion engine may be coupled to the cutting blade via a friction drive, wherein the friction drive is configured with a neutral bearing in order to reduce flat spotting of components of the friction drive.
摘要:
An inverter circuit for a brushless motor utilizes an IPM integrated circuit module. The module includes insulated gate bipolar transistors and has outputs for providing driving signals to the brushless motor based on control signals received at inputs from a microcontroller. A sensing circuit measures the current at the lines from the outputs of the IPM integrated circuit module to the motor. A feedback circuit processes the current measurements and provides signals corresponding to the measured current to the microcontroller.
摘要:
A computer-implemented method of design of ruled surfaces may comprise the step of accessing data defining guiding curves P(u) and Q(v) and a cost function ƒ(t,w). Given P(u) and Q(v), the unknown coupling is a parameterized curve s(t(s),w(s)). The method further comprises defining an objective function of the type J=J(ƒ,t,w), involving both ƒ(t,w) and coordinates t, w of the coupling curve. Then, optimizing the objective function J makes it possible to obtain the target coupling curve. Finally, a ruled surface S(s,λ)=λQ(w(s))+(1−λ)P(t(s))is provided, according to the guiding curves P(t(s)) and Q(w(s)), composed with the coordinates t,w of the coupling curve previously obtained. In addition, the objective function is further constrained at the optimization step such that arguments t,w of the cost function ƒ(t,w) are regulated by a regulation function μ.
摘要:
An electronic control circuit controls a brushless DC motor. It includes an input power supply control circuit. A microcontroller integrated circuit has control functions to control a brushless DC motor. Additional control functions are provided by software program instructions, which when executed, cause the microcontroller integrated circuit to perform additional control functions for the brushless DC motor.
摘要:
A method is provided for designing a 3D modeled object comprising the steps of providing at least one surface defined by a field of points of the surface and a field of normal vectors normal to the surface; and watermarking the object by modifying the field of points while keeping the field of normal vectors as it is. Such a method provides a technique for tracing a 3D modeled object modeled at least by a field of points of a surface and a field of normal vectors normal to the surface.
摘要:
An electronic control circuit for a brushless motor has an input power circuit providing a DC voltage and a microcontroller integrated circuit receiving the DC voltage. The microcontroller integrated circuit provides three-phase control signals according to a space vector control method. A microprocessor connected to the microcontroller integrated circuit executes supervisory control over the electronic control circuit. An inverter circuit receives the three-phase control signals from the microcontroller integrated circuit and provides driving signals to the brushless motor based on the three-phase control signals received from the microcontroller integrated circuit.
摘要:
A method is provided for designing a 3D modeled object comprising the steps of providing at least one surface defined by a field of points of the surface and a field of normal vectors normal to the surface; and watermarking the object by modifying the field of points while keeping the field of normal vectors as it is. Such a method provides a technique for tracing a 3D modeled object modeled at least by a field of points of a surface and a field of normal vectors normal to the surface.
摘要:
A power factor correction circuit has a semiconductor integrated circuit and at least one very low Rds(on) MOSFET. The circuit also includes a silicon carbide diode for zero reverse recovery current.
摘要:
An electronic control circuit for a brushless motor has an input power circuit providing a DC voltage and a microcontroller integrated circuit receiving the DC voltage. The microcontroller integrated circuit provides three-phase control signals according to a space vector control method. A microprocessor connected to the microcontroller integrated circuit executes supervisory control over the electronic control circuit. An inverter circuit receives the three-phase control signals from the microcontroller integrated circuit and provides driving signals to the brushless motor based on the three-phase control signals received from the microcontroller integrated circuit.