Analysis and design of stator terminals reversal connection detector for Synchro-to-Digital converter
In this paper, a stator terminals reversal connection detector is presented for Synchro-to-Digital Converter (SDC). This is useful for identifying inadvertent reversal connection of synchro output signals to SDC. Synchro is a positional sensor excited by a sinusoidal signal and gives three electrical signals. The zero crossing outputs of synchro and a clock based on synchro excitation signal are generated. Then the phase relationship between excitation and synchro output signals is analyzed for possible stator terminal reversal connections between synchro and SDC. This method uses simple electronic components such as operational amplifiers, monoshots and flip flops. The analysis, implementation and experimental results are presented.
A new approach for synchro shaft position measurement using pulse width modulation
In this paper, an angle measurement system for a synchro transmitter is presented. It is based on the concept of pulse width modulation, which enables determination of the shaft angle of a synchro transmitter. A dedicated electronic scott-T gives the resolver format signals from a synchro transmitter. Triangular signal is used along with scott-T sine, cosine signals to generate pulse width modulated signals. The linear evaluation of time duration window (TDW), the quadrant detection and shaft angle in digital form demonstrates the effectiveness of the proposed converter. The measurement system is designed using op-amps, complex programmable logic device (CPLD) and a microcontroller. The microcontroller software design is also introduced. The experimentation on designed board with real synchro’s outputs has been demonstrated to validate the proposed approach.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.