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.
The Application of Synchro Transmitter in the Material Distribution Angle Control of a Blast Furnace
A material charging system is a critical process in a blast furnace. Raw materials are transported from the stock house to the top of furnace and distributed into the furnace. To put defined amounts of materials into the preset position, the control and detection of angular positions of flow control valves and the distributing chute on the top of the furnace is crucial. A synchro transmitter, used in combination with a synchro indicator, provides remote indication and control of the opening of valves, gates, dampers, and mobile equipment. In the proposed system, the synchro transmitter outputs a three-phase signal. The signal is finally transformed into a digital angular signal. By appropriate PLC control codes, the signal is a mapping of real mechanical angles or traveling length for operation and control. As a real application in a blast furnace, it is proved a robust, environment insensitive and stable solution of angle measurement and process control.
A New Low Cost Linear Resolver Converter
A new low cost converter topology is proposed for sinusoidal position encoders. The converter enables determination of the angle from the sine and cosine signals of the encoder. When used with resolvers, the implementation of the present scheme takes advantage of the available excitation signal used to operate the device. This trigonometric reference signal is optimally used to generate an analogue signal equivalent to a digital look-up table (LUT). This enables determination of the mechanical angle without using LUT, A/D, and D/A converters. The scheme is optimized in order to achieve highest possible precision. Beside simplicity of its implementation, the proposed converter offers the advantage of robustness to amplitude fluctuation of the transducer excitation signal. The converter was implemented using ordinary low-cost analog components. The theory of operation, computer simulation, and experimental results are given.