Rotational Speed Measurement Based on LC Wireless Sensors

This article presents a method for detecting rotational speed by LC (inductor-capacitor) wireless sensors. The sensing system consists of two identical LC resonant tanks. One is mounted on the rotating part and the other, as a readout circuit, is placed right above the rotating part. When the inductor on the rotating part is coaxially aligned with the readout inductor during rotation, the mutual coupling between them reaches the maximum, resulting in a peak amplitude induced at the readout LC tank. The period of the readout signal corresponds to the rotation speed. ADS (Advanced Design System) software was used to simulate and optimize the sensing system. A synchronous detection circuit was designed. The rotational speed of an electric was measured to validate this method experimentally, and the results indicated that the maximum error of the rotation speed from 16 rps to 41 rps was 0.279 rps.

Manipulating neural dynamics to tune motion detection

Neurons integrate excitatory and inhibitory signals to produce their outputs, but the role of input timing in this integration remains poorly understood. Motion detection is a paradigmatic example of this integration, since theories of motion detection rely on different delays in visual signals. These delays allow circuits to compare scenes at different times to calculate the direction and speed of motion. It remains untested how response dynamics of individual cell types drive motion detection and velocity sensitivity. Here, we sped up or slowed down specific neuron types in Drosophila's motion detection circuit by manipulating ion channel expression. Altering the dynamics of individual neurons upstream of motion detectors changed their integrating properties and increased their sensitivity to fast or slow visual motion, exposing distinct roles for dynamics in tuning directional signals. A circuit model constrained by data and anatomy reproduced the observed tuning changes. Together, these results reveal how excitatory and inhibitory dynamics jointly tune a canonical circuit computation.

A Demodulation Circuit For Analog Front End Of Passive Tag Chip

The demodulation circuit designed in this paper is suitable for the analog front end of passive UHF RFID tag chip, which can handle ASK signals with large changes in amplitude, modulation depth and signal frequency. Its performance meets the requirements of standards ISO/IEC 18000-6C and GB/T 29768-2013. Envelope detection circuit and limiter circuit are simple in structure and do not consume power. The comparison reference voltage is taken according to the average value of the envelope high and low levels, and is less affected by the dynamic changes of the input signal. Changing the width-to-length ratio of the MOSFETs in the feedback path of the comparator can adjust the hysteresis, with strong noise suppression and controllable sensitivity. The demodulator is implemented with TSMC 0.18 μm standard CMOS process. The simulation results show that the ASK signal modulation depth that the demodulator can handle is as low as 30%, and the maximum pulse width demodulation error is only 0.43%.

The Impact of Temperature of the Tripping Thresholds of Intrusion Detection System Detection Circuits

This research paper discusses issues regarding the impact of temperature on the tripping thresholds of intrusion detection system detection circuits. The objective of conducted studies was the verification of a hypothesis assuming that the variability of an intrusion detection system’s (considered as a whole) operating environment temperature can impact the electrical parameters of its detection circuits significantly enough so that it enables a change in the interpretation of the state observed within a given circuit fragment from the state of “no circuit violation” to “circuit violation”. The research covered an intrusion detection system placed in a climatic chamber with adjusted temperature (−25.1 ÷ +60.0 [°C]). The analysis of the obtained results enabled determining the relationships that allow selecting detection circuit resistor values. It is important since it increases the safety level of protected facilities through proper resistor selection, thus, correct interpretation of a detection circuit state.

Fault-tolerant Structures of Digital Devices Based on Boolean Complement with the Calculations Checking by Sum Codes

The article considers the construction of fault-tolerant digital devices and computing systems that does not use the principles of introducing modular redundancy. To correct the signals, a special distorted signal fixation unit, concurrent error-detection by the pre-selected redundant code circuit, as well as a signal correction block are used. The distorted signal fixation unit is implemented by the Boolean complement method, which makes it possible to design a large number of such blocks with different indicators of technical implementation complexity. When synthesizing a fault-tolerant device according to the proposed method, it is possible to organize a concurrent error-detection circuit for both the source device and the Boolean complement block in the structure of the distorted signal fixation unit. This makes it possible to choose among the variety of ways to implement fault-tolerant devices according to the proposed method, one that gives a device with the least structural redundancy. Various redundant codes can be used to organize concurrent error-detection circuits, including classical and modified sum codes. The author provides algorithms for the synthesis of distorted signal fixation unit and the Boolean complement block. The results of experimental researches with combinational benchmarks devices from the well-known LG’91 and MCNC Benchmarks sets are highlighted. The article presents the possibilities of the considered method for the organization of faulttolerant digital devices and computing systems.

A Detection Circuit for Improving the Unloading Transient Performance of the COT Controller

Fast load transient response and high light-load efficiency are two key features of the constant on-time (COT) control technique that has been widely used in numerous applications, such as for voltage regulators and point-of-load converters. However, when load step-down occurs during an on-time interval, the COT controller cannot respond until the COT interval expires. This delay causes an additional output voltage overshoot, resulting in unloading transient performance limitation. To eliminate the delay and improve the unloading transient response of the COT controller, a load step-down detection circuit is proposed based on capacitor current COT (CC-COT) control. In the detection circuit, the load step-down is monitored by comparing the measured capacitor current with the preset threshold voltage. Once the load step-down is monitored, the on-time is promptly truncated and the switch is turned off. With the proposed detection circuit, the CC-COT-controlled buck converter can monitor the load step-down without any delay and obtain less output voltage overshoot when the load step-down occurs during the on-time interval. PSIM circuit simulations are employed to demonstrate the feasibility of the detection circuit.

Designing a Partly Self-Powered Keyboard Based on Triboelectric Effect

The purpose of this paper is to design a keyboard using the triboelectric effect (Tribo Electric Nano Generator - TENG) to collect a part of the energy from keystrokes to reduce the power consumption of the keyboard. Using elastic material as the cover on the keyboard to maximize the capture of energy from typing. The keyboard layers are made from common materials such as Al (Aluminum) and PTFE (Polytetrafluoroethylene). The built-in 16-button keyboard ensures the same typing speed as a typical keyboard. Based on selected triboelectric material, the output voltage of keyboard was simulated and processed by using a signal detection circuit. The results show that the average voltage generated by each key with electrical friction effect is about 4 V, the power consumption for the detection circuit is about 0.32 W. In addition, the keystroke signals were sent and displayed correctly on the designed software on the computer.