A CPLD-based long-duration pulse generator, which can generate singular or continuous pulse with ultra-low repetition rate/long cycle, is introduced in this paper. The cycle (T) of output pulses generated by this gene...
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A CPLD-based long-duration pulse generator, which can generate singular or continuous pulse with ultra-low repetition rate/long cycle, is introduced in this paper. The cycle (T) of output pulses generated by this generator can be selected in a range from Tmin=1 ms to Tmin>1000 s. Also, the width of the output pulse can be adjusted from 1/1000 cycle to 999/1000 cycle stepped by 1/1000 cycle. Accuracy of the repetition rate (f) of output pulses is less than or equal 0.02 [per mille] , and the long-term instability is within ±0.01 [per mille] . There are two modes selectable for output pulses, singular pulse output and repetitive pulse output, which can be set by a two-position switch. When the singular pulse output mode is selected, only one pulse can be generated each time by pressing an external control push-button. This pulser can provide both TTL/T over-bar T over-bar L over-bar output signals and NIM/N over-bar I over-bar M over-bar output signals. The rise time of the NIM output signal is tr less than or equal 4 ns and the fall time is tf less than or equal 4 ns. We use CPLD to construct the main circuits. Compared with the circuits constructed by TTL devices, the new pulse generator has features such as less components, lower cost and lower dissipation.
The Lighting Detection and Orientation System is a lighting image sensor to detect the distribution and variability of total lighting. A digital image processor scheme with CPLD+DSP is used in the system, because CPLD...
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The Lighting Detection and Orientation System is a lighting image sensor to detect the distribution and variability of total lighting. A digital image processor scheme with CPLD+DSP is used in the system, because CPLD is used as a complex programmable logic device and DSP is used as the abbreviation of digit signal processor. Image signal collection, decoder and memory are controlled by CPLD, which can reduce the area of circuit board and make the structure of circuit board easier;and large member of image data in real-time can be managed with DSP because of its high speed digital processor characteristic.
A kind of data acquisition system based on universal serial bus (USB) was designed which was used to acquire well logging analog data. Characteristics and advantages about USB were discussed. The whole components by w...
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A kind of data acquisition system based on universal serial bus (USB) was designed which was used to acquire well logging analog data. Characteristics and advantages about USB were discussed. The whole components by which realize analog signal acquisition were analyzed. The system is composed of hardware design, firmware design, device driver and application software design. USB driver stack and the method of opening a USB device were also analyzed. The results show that the precision of the system is not less than 13 bits, and its control function is flexible, and can be extended easily.
The paper presents modern programmablelogicdevices and design methodologies with appropriate tools reference. It briefly shows enhancements introduced in the architecture of FPGA and its influence on circuit capabil...
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The paper presents modern programmablelogicdevices and design methodologies with appropriate tools reference. It briefly shows enhancements introduced in the architecture of FPGA and its influence on circuit capabilities. The paper presents also the design process from idea to functional implementation. It discusses algorithmic and functional approaches to design. Abstraction level and transaction mechanisms are shown as a method of hiding details without compromising design functionality. Finally tools for different design approaches and design environment requirements are presented.
Potential applications of Electrical resistance tomography (ERT) are restricted by many factors. Furthermore, with the development of industrial field,ERT system has been required to be a kind of visu
Potential applications of Electrical resistance tomography (ERT) are restricted by many factors. Furthermore, with the development of industrial field,ERT system has been required to be a kind of visu
The paper introduces a Fuzzy controller by in-system programmablelogic circuit. The fuzzy transformation of input accurate data, Fuzzy control rules based on observing the control action and the user's experience...
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ISBN:
(纸本)0780372689
The paper introduces a Fuzzy controller by in-system programmablelogic circuit. The fuzzy transformation of input accurate data, Fuzzy control rules based on observing the control action and the user's experience and Fuzzy decision of output can be carried out by the programmabledevice. Owing to using VHDL language to write Fuzzy rules, the characteristic of this controller is the Fuzzy rules can be modified at any moment even if at work. The paper gives the controller's working principle and the source code of VHDL.
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