Li Weisen

Bio: Li Weisen is an academic researcher. The author has contributed to research in topics: Oscilloscope & Signal. The author has an hindex of 11, co-authored 492 publications receiving 1353 citations.

Digital oscillograph and its waveshape displaying method

Abstract: The invention provides a display method for waveform of digital oscillograph and the digital oscillograph. It includes: wave form data collecting process or device to make the display data of display buffer before changing the horizontal timebase set as the data source of display data in changing the horizontal timebase; the waveform data zoom process or device is to zoom the display data on screen last time; waveform display process or device is to copy the zoomed data to the waveform display buffer in the state of digital oscillograph system stop and display it on screen. The invention is to display and treat the waveform data in changing the horizontal timebase by combining the collect data and waveform display of digital oscillograph to reflect the waveform data in time of changing the horizontal timebase.

Oscilloscope provided with attenuator circuit

Abstract: The invention relates to an oscilloscope provided with an attenuator circuit, which comprises a signal input module, an input attenuation module, a programmable amplifier, a bandwidth limit module, an ADC driving module, an A/D conversion module, a control processing module and a D/A conversion module which are sequentially connected with each other in series, wherein the input attenuation modulecomprises a resistance-capacitance network provided with a plurality of branch circuits, a switch unit and an operational amplifier unit which are sequentially connected with each other in series, wherein the operational amplifier unit comprises a compensating network, and the control processing module can realize the adjustment of frequency response of an input signal of the oscilloscope by using the compensating network. By adopting the controllable compensating network, the frequency response of the input signal of the oscilloscope can be adjusted, and thereby the invention has good flatness on the frequency response.

Digital oscilloscope with equivalent sampling functions

Abstract: The utility model discloses a digital oscilloscope with an equivalent sampling function, which comprises a narrow-pulse amplifying circuit 21 and a control circuit 22 used for calculating narrow-pulse width according to pulse signals output by the narrow-pulse amplifying circuit. The narrow-pulse amplifying circuit 21 is provided with a charging current source 211, a discharging current source 212 of which the on and off states are controlled by narrow pulse, a sampling capacitor 213, and a comparator circuit 214. The charging current source 211 is used for supplying charging current to the sampling capacitor 213 constantly, and the charging current is appointed by a control circuit 22; the discharging current source 212 of which the on and off states are controlled by the narrow pulse provides a discharging current larger than the charging current to the sampling capacitor 213 when the narrow pulse comes; and the comparator circuit 214 outputs pulse signals to the control circuit 22 according to the condition that whether the voltage on the sampling capacitor 213 exceeds threshold voltage or not. The utility model can be used for expanding and measuring very narrow pulse, the module is made up of a simple hardware circuit, and the cost is reduced.

Digital oscilloscope with equivalent sampling function, and equivalent sampling method for digital oscilloscope

Abstract: The invention discloses a digital oscilloscope with an equivalent sampling function The digital oscilloscope comprises a clock source module for generating a sampling clock signal, a triggering module for generating a triggering signal, a sampling module for receiving a measured signal and the sampling clock signal and generating a plurality of sampled data, a phase difference measuring module for generating a phase adjusting signal, and a phase adjusting module for adjusting the displayed positions of the plurality of sampled data according to the phase adjusting signal, wherein the phase difference measuring module comprises a delay chain module for receiving the triggering signal, delaying the triggering signal according to a plurality of different delay values and generating a plurality of delayed signals and a triggering output module for receiving the delayed signals and the sampling clock signal, and outputting the phase adjusting signal according to levels of the delayed signals at the triggering moment of the sampling clock signal under the triggering of the sampling clock signal The digital oscilloscope consists of digital circuits, and cannot be influenced by factors, such as noise and the like; and the waveform fluctuation degree is low

Multi-axis interface for a touch-screen enabled wearable device

Abstract: A touchscreen-enabled wearable computer includes a multi-axis user interface provided by at least one software component executing on a processor. The multi-axis user interface comprises at least two user interface regions displayed on the touchscreen one at a time, each displaying a series of one or more application screens; and a combination of a vertical navigation axis and a horizontal navigation axis, wherein the vertical navigation axis enables a user to navigate between the multiple user interface regions in response to vertical swipe gestures made on the touchscreen, and the horizontal navigation axis enables the user to navigate the application screens of a currently displayed user interface region in response to horizontal swipe gestures across the touchscreen.

Device identifier similarity models derived from online event signals

Abstract: A computerized method and system operable to build a device identifier similarity model with online event signals and determine similar network device identifiers. A processing circuit receives a first set of network device identifiers. The processing circuit represents each network device identifier of the first set by feature data associated with each network device identifier's network activity, where the feature data is associated with the content clicked-on or converted-on. The processing circuit applies abstractions on the feature data to form concepts. The processing circuit derives at least one hierarchy of feature data based on the keywords and concepts of the feature data. The processing circuit expands the feature data based on the derived at least one hierarchy of feature data and generates the device identifier similarity model based on the expanded feature data. The processing circuit is also capable of determining long-term and short-term history events.

Method for sequencing a heteropolymeric target nucleic acid sequence

Abstract: The invention relates to a method for sequencing a heteropolymeric target nucleic acid sequence that involves stochastic sensing. The invention also relates to a method for improving a pore for sequencing a target nucleic acid sequence by modifying one or more sites in the pore.

Mutant lysenin pores

Abstract: The invention relates to mutant forms of lysenin. The invention also relates to analyte characterisation using lysenin.

Capacitance measurement circuit with dynamic feedback

Abstract: Methods, devices, and systems that measure capacitance are disclosed. Typically, an accumulator circuit couples to the capacitance and includes an accumulator and switch(es) that charge the accumulator over a series of switch-controlled charging or discharging cycles governed by a first control signal. The accumulator circuit provides an accumulator signal based on the charge on the first accumulator. A discharge circuit couples to the accumulator circuit and includes an optional variable current device, the discharge circuit partially discharging the accumulator based on a second control signal. A control circuit, which couples to the accumulator circuit and the discharge circuit, dynamically adjusts the first and/or second control signals to keep the accumulator signal in a desired range. The dynamically adjusted control signal can be used as a measure of the capacitance. Such methods and systems may be used in capacitive touch sensing devices such as capacitive buttons and capacitive touch panels.