Abstract: A switch circuit includes a first audio input pin configured to receive a first audio signal having a first amplitude, a second audio input pin configured to receive a second audio signal having a second amplitude, an input pin, an output pin, and at least one switch configured to convert the input voltage to the output voltage. When a maximum of the first amplitude and the second amplitude is lower than a first threshold voltage, the output voltage is a default voltage. When the maximum of the first amplitude and the second amplitude is greater than the first threshold voltage but lower a second threshold voltage that is greater than the first threshold voltage, the output voltage is a first voltage greater. When the maximum of the first amplitude and the second amplitude is larger than the second threshold voltage, the output voltage is a second voltage.

Abstract: A power switch device with cascode structure provides better performance with simple design. It has a normally-on device and a normally-off device coupled in series. A resistor is coupled to a control terminal of the normally-on device; and a capacitor is coupled between a control terminal of the normally-off device and the control terminal of the normally-on device.

Abstract: The present invention discloses an automatic grinding device for weld beading on the inner wall of a pipeline with a large length to diameter ratio. The automatic grinding device includes a supporting module, and a walking module, a working module and a control module which are arranged on the supporting module, where the walking module is used for moving the supporting module to the butt welding position of the pipeline; the working module is used for grinding the weld beading; and the control module is used for controlling the actions of the walking module and the working module. When the pipeline rotates along the axial direction, the position of the grinding device can remain at the bottom of the pipeline, rather than rotating together with the pipeline, and the elimination of weld beading on the whole circumference at the butt welding position of the pipeline is realized.

Abstract: The present invention discloses an automatic grinding device for weld beading on the inner wall of a pipeline with a large length to diameter ratio. The automatic grinding device includes a supporting module, and a walking module, a working module and a control module which are arranged on the supporting module, where the walking module is used for moving the supporting module to the butt welding position of the pipeline; the working module is used for grinding the weld beading; and the control module is used for controlling the actions of the walking module and the working module. When the pipeline rotates along the axial direction, the position of the grinding device can remain at the bottom of the pipeline, rather than rotating together with the pipeline, and the elimination of weld beading on the whole circumference at the butt welding position of the pipeline is realized.