scholarly journals Comparative Study of DDS with Different Types of Phase Accumulators

Inventions ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 35
Author(s):  
Oleksiy Polikarovskykh ◽  
Lesia Karpova ◽  
Ihor Hula ◽  
Vasyl Melnychuk
Keyword(s):  
Signal Transmission ◽  
Block Length ◽  
Maximum Output ◽  
Output Frequency ◽  
Direct Digital Synthesizer ◽  
Transfer Delay ◽  
Variable Block ◽  
Different Types ◽  
Parallel Transfer ◽  
Transfer Signal

The paper deals with the problems of delayed transfer signals in the direct digital synthesizer (DDS) phase accumulator adders. Transfer delay is one of the factors that affect the maximum output frequency of the DDS synthesizer. The main types of adders used in DDS synthesizers are described. Separately, attention was paid to the adder with a consistent transfer of the transfer signal, adders with a transmission carry signal with a fixed block length, adders with a signal transmission delay with a variable block length, and a mathematical analysis of the origin and duration of the delay of the transfer signal in them. It was found that the use of a transfer adder with a variable length of a block in the core of a direct digital synthesizer would increase the maximum output frequency by 2.4 times compared to the adder with a parallel transfer, and by 1.43 times as compared with the adder with a fixed length the block.

Induction Heating Power Supplies

1988 ◽  
pp. 47-75
Keyword(s):  
Induction Heating ◽  
Maximum Output Power ◽  
Heating System ◽  
Power Supplies ◽  
Maximum Output ◽  
Frequency Multipliers ◽  
Ac Power ◽  
Different Types ◽  
Two Factors ◽  
Induction Heating System

Abstract Besides the induction coil and workpiece, the induction generator (source of ac power) is probably the most important component of an overall induction heating system. Such equipment is typically rated in terms of its frequency and maximum output power (in kilowatts). This chapter addresses the selection of power supplies in terms of these two factors as well as the operational features of different types of sources. The six different types of power supplies for induction heating applications covered in this chapter are line-frequency supplies, frequency multipliers, motor-generators, solid-state (static) inverters, spark-gap converters, and radio-frequency power supplies. The chapter discusses the design and characteristics of each of the various types of power supplies.

Assessing Short‐Term Clock Errors and Drifts of Temporary Seismic Networks Using the Active Airgun Source in Binchuan, Yunnan

2019 ◽  
Vol 90 (6) ◽  
pp. 2165-2174 ◽  
Author(s):  
Jinzhong Jiang ◽  
Runhai Yang ◽  
Bin Wang ◽  
Ya Xiang ◽  
Weidong Pang ◽  
...  
Keyword(s):  
Seismic Data ◽  
Matched Filter ◽  
Signal Transmission ◽  
P Wave ◽  
Filter Method ◽  
Short Term ◽  
Hardware Failure ◽  
Different Types ◽  
Station Pair ◽  
Seismic Networks

ABSTRACT We conducted a short‐term airgun experiment at the Binchuan Fixed Airgun Signal Transmission Station from 14 to 20 February 2017, and two different types of seismometers (Güralp CMG‐40T and QS05A) recorded 62 airgun shots triggered under the same conditions. However, we observed significant clock errors and drifts in seismic data recorded by four QS05A seismometers. To assess the short‐term clock errors and drifts for seismometers, we propose a new method that measures the P‐wave arrival‐time differences between airgun signals recorded at a station pair, using the matched filter method. We find ∼1.0  s absolute clock errors for two Güralp CMG‐40T stations (CKT2 and 53261) and one QS05A station (STA05), as well as ∼0.5  s timing leaps for four QS05A stations (STA19, STA21, STA31, and STA33) during the experiment. Furthermore, all the QS05A seismometers exhibit clock drifts with similar linear trends. Additionally, we use teleseismic waveforms to verify the absolute clock errors for stations CKT2, 53261, and STA05. After double‐checking several possible factors, we determine the hardware failure or malfunctioning that may cause clock errors for the two types of seismometers.

scholarly journals Toward Better PV Panel’s Output Power Prediction; a Module Based on Nonlinear Autoregressive Neural Network with Exogenous Inputs

2019 ◽  
Vol 9 (18) ◽  
pp. 3670 ◽  
Author(s):  
Natsheh ◽  
Samara
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Output Power ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Atmospheric Conditions ◽  
Power Prediction ◽  
Different Types ◽  
Artificial Neural ◽  
Nonlinear Autoregressive

Much work has been carried out for modeling the output power of photovoltaic panels. Using artificial neural networks (ANNS), one could efficiently model the output power of heterogeneous photovoltaic (HPV) panels. However, due to the existing different types of artificial neural network implementations, it has become hard to choose the best approach to use for a specific application. This raises the need for studies that develop models using the different neural networks types and compare the efficiency of these different types for that specific application. In this work, two neural network types, namely, the nonlinear autoregressive network with exogenous inputs (NARX) and the deep feed-forward (DFF) neural network, have been developed and compared for modeling the maximum output power of HPV panels. Both neural networks have four exogenous inputs and two outputs. Matlab/Simulink is used in evaluating the proposed two models under a variety of atmospheric conditions. A comprehensive evaluation, including a Diebold-Mariano (DM) test, is applied to verify the ability of the proposed networks. Moreover, the work further investigates the two developed neural networks using their actual implementation on a low-cost microcontroller. Both neural networks have performed very well; however, the NARX model performance is much better compared with DFF. Using the NARX network, a prediction of PV output power could be obtained, with half the execution time required to obtain the same prediction with the DFF neural network, and with accuracy of ±0.18 W.

Collisional Transfer of Rotational Energy in Mixtures of Methanol with Ne, Ar, and D2

1975 ◽  
Vol 53 (23) ◽  
pp. 2617-2621
Author(s):  
S. S. Haque ◽  
R. M. Lees
Keyword(s):  
Steady State ◽  
Qualitative Analysis ◽  
Rate Constant ◽  
Double Resonance ◽  
Rotational Energy ◽  
Different Types ◽  
Transfer Signal

Steady state microwave double resonance experiments are reported for dilute mixtures of CH3OH in excess Ne, Ar, and D2. The results for Ne and Ar are, in general, similar to previous results for He, and those for D2 to H2, with both classes of collision partners displaying a decrease in collisional transfer signal with increasing mass of the partner. A simple qualitative analysis indicates that the ratios between the rates of different types of collision-induced transitions are quite similar for the members of a class. For He, Ne, and Ar, the rate constant for Δk = 0 transitions is of the order of 8 times that for a Δk = ±1 transition, while for H2 and D2 the ratio is about 4.

Architecture for decoding adaptive Reed-Solomon codes with variable block length

2002 ◽  
Vol 48 (3) ◽  
pp. 631-637 ◽  
Author(s):  
Mook Kyou Song ◽  
Eung Bae Kim ◽  
Hee Sun Won ◽  
Min Han Kong
Keyword(s):  
Block Length ◽  
Reed Solomon Codes ◽  
Variable Block

Realization of Multi-Channel, High-Speed Waveform Generator Based on FPGA

2012 ◽  
Vol 182-183 ◽  
pp. 506-510
Author(s):  
Hong Shan Nie ◽  
Hu Sheng Liu ◽  
Yu Mei Zhang ◽  
Qi You Xie ◽  
Qiang Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Maximum Output ◽  
Small Signal ◽  
Clock Generator ◽  
Waveform Generator ◽  
Output Frequency ◽  
Digital To Analog Converter ◽  
Multi Stage ◽  
Analog Converter ◽  
Signal Type

This paper introduces the design and realization of a multi-channel high-speed waveform generator based on FPGA, Which consists of the high-speed clock generator, the high-speed high-precision digital to analog converter, multi-stage pipeline accumulator and high-speed small signal conditioning. At last, it gives some simulation. The results show that the output signal type of this waveform generator is rich, and the maximum output frequency is 80MHz. The waveform generator can be used in the fields which require multi-channel high-speed signal, such as phased array radar.

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