32results about How to "Constant value" patented technology

For applying a driving current to a motor, an H-bridge circuit is constructed by a first and a second switching unit and a first and a second linear unit. An error amplifier generates an error signal representative of a difference between the driving current detected by a current detecting circuit and a command current signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving current to become proportional to the command current signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

A toasting appliance includes a toasting chamber, a heating element for heating a foodstuff located within the toasting chamber, an optical system having a first light source for illuminating the foodstuff with light having a first wavelength and an optical receiver for detecting light reflected from the foodstuff. A second light source is provided for illuminating at least the optical receiver with light having a second wavelength different from the first wavelength. A controller varies the intensity of the light emitted from the second light source during a toasting operation.

For applying a driving voltage to a motor, an H-bridge circuit is constructed by a first and a second linear unit and a first and a second switching unit. An error amplifier generates an error signal representative of a difference between the driving voltage detected by a voltage detecting circuit and a command voltage signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving voltage to become proportional to the command voltage signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

A method, a mandrel and a device for removing coreless rolls of a plastic film. The mandrel comprises a tubular body having a plurality of radial holes, conformed with a chamber for distributing pressurized air, in which a piston suitable for being magnetically coupled with an external drive member slides. When a roll must be removed, pressurized air is supplied to the fore end of the mandrel, and escapes from all the holes to expand the internal turns of the roll which can be taken off without friction. As the roll advances along the mandrel, the magnetically driven piston progressively reduces the volume of the air chamber preventing at the same time the air to escape from the holes that progressively come to lie on the rear side of the mandrel, with consequent saving of compressed air.

A touch display device is disclosed, including a display panel and a touch layer, a sealant disposed between the touch layer and the display panel, the sealant, the touch layer, and the display panel forming a sealed cavity. An air pressure intensity inside the sealed cavity is less than a preset value.

The invention relates to a cam climbing mechanism. A motor and a speed reducer are connected and are installed on a machine frame together, an output shaft of the speed reducer is provided with a driving sprocket, a first cam shaft is installed through a bearing in a bearing bracket which is located at one end of the top of the machine frame, a first sprocket is fixed arranged on the first cam shaft, and a short chain is sleeved on the driving sprocket and the first sprocket. A second cam shaft is arranged in a bearing bracket which is located at the other end of the top of the machine frame through a bearing, a second sprocket is fixedly arranged on the second cam shaft, and a long sprocket is sleeved on the first sprocket and the second sprocket. The lifting frame is placed on the machine frame, and a limit guide mechanism which enables the lifting frame to move in a lifting mode is arranged between the lifting frame and the machine frame. Work piece supporting plates are respectively arranged at two ends of the top of the lifting frame, support wheels are respectively arranged at two ends of the bottom of the lifting frame, and support wheels which are arranged at two ends of the bottom of the lifting frame are respectively arranged on an eccentric cam of the first cam shaft and an eccentric cam of the second cam shaft. The cam climbing mechanism has the advantages of being reasonable in structure, capable of achieving stable ejecting or descending of a tool support, constant in journey, safe and reliable.