| 摘要 |
PROBLEM TO BE SOLVED: To achieve an inexpensive and reliable circuit, by configuring a circuit with three sets of primary filters and AC-coupling circuits being connected to each of armature coil wirndings, three sets of adders for obtaining the sum of processed three phases, and three sets of comparators. SOLUTION: An adder 18 of a position detection circuit obtains the sum of three phases where the three phases of a waveform excluding the DC content from each filter output are connected by three resistors with different values, and is a circuit for generating a reference voltage for comparison. Also, a primary filter, an AC-coupling circuit, and a comparator before and after the circuit have been used conventionally. Also, the all waveforms of the three phases are inputted to the adder 18 to create a comparison reference voltage, thus achieving a comparison where the offset voltage among three phases being generated due to, for example, the scattering of circuit parts and hence obtaining an accurate position detection signal with inexpensive circuit parts and achieving an inexpensive and reliable circuit. |
