DIVIDING*READING CIRCUIT FOR SINE SIGNAL

摘要

PURPOSE:To simplify a circuit configuration by providing a division circuit taking a ratio of both signals and a conversion circuit to make the output correspond to displacement on a circuit to divide sine wave signals 90 deg. different in phase according to a positional change and read a finer displacement. CONSTITUTION:Sine wave signals e0, e90 90 deg. different in phase according to a positional change are inputted to an up-down counter 8 by way of zero-cross detection circuits 2, 4 and an AD converter 6, and the positional change at every 180 deg. is counted. On the other hand, the signals e0, e90 are inputted to AD converter 10, 12, a signal obtainable through digital signal operation of eD0/eD90 is outputted to an arithmetic circuit 16 from a division circuit 14, and an inverse tangent signal to the ratio is outputted to an arithmetic circuit 18 from the circuit 16. A signal converted into a displacement at every 180 deg. through the circuit 18 is sent to an adder 20. On the other hand, an output signal from the circuit 18 and a signal of a counter 80 through a synchronizing signal from a gate circuit 30 based on a signal from the zero-cross detection circuits are inputted to the adder 20, and a displacement according to the sum of both input signals is indicated on a display 22. A circuit configuration is simplified accordingly.