摘要:
When a driver unit is in a high impedance state as viewed from a first coil or a second coil, an induced voltage detector detects the voltage across the first coil or that across the second coil so as to detect an induced voltage occurring in the first coil or the second coil. The induced voltage detector includes a differential amplifier circuit for differentially amplifying an electric potential across the first coil or that across the second coil, and an analog-to-digital converter circuit for converting an analog value outputted from the differential amplifier circuit into a digital value and outputting the converted digital value to a control unit. The control unit generates a drive signal based on an input signal set externally and adjusts the drive signal in accordance with the induced voltage detected by the induced voltage detector so as to set the adjusted drive signal in the driver unit.
摘要:
A motor speed controller detects out-of-control reverse rotation of a motor even when the pulse signal obtained from the motor and synchronized with the rotation is of only one kind. A target instruction signal is generated on the basis of a target rotational speed ωT of the motor. A compensation instruction signal is generated on the basis of an error signal Ve that corresponds to a difference between the actual rotational speed ω and ωT. A composite signal is generated by combining above two instruction signals. A state in which the control direction of the composite signal with respect to ω is the reverse of the direction of ωT, and the strength of the composite signal exceeds a designated threshold continues for a designated period, is judged as a state of out-of-control reverse rotation, and restoration to the normal state is performed.
摘要:
A coil current detector detects a current component flowing through a coil. A scaling unit scales a drive signal. An induced voltage component extraction unit extracts an induced voltage component by removing the drive signal, scaled by the scaling unit, from the coil current component detected by the current detector. A phase difference detector detects a phase difference between the phase of the drive signal and that of the induced voltage component. A signal adjustment unit adjusts the drive signal so that the phase difference detected by the phase difference detector can be brought close to a target phase difference.
摘要:
A differential amplifier detects a coil current Is at the time of steady rotation of a synchronous motor. An application voltage S0 at this time is detected from an output of an ATT circuit and so on. With the use of the coil current Is which is detected, the application voltage S0 at that time, and a predetermined scaling factor As, an induced current Ib is obtained based on Ib=As·S0−Is. The application voltage to the motor is controlled based on the induced current Ib which is obtained.
摘要:
In a motor speed controller, feedback control is implemented at a gain independent of the target rotational speed ωT while the increase in the circuit size or processing load is reduced. The rotational speed ω of the motor is controlled on the basis of a pulse signal in which a pulse period τP varies in inverse proportion to ω. A count clock generation circuit varies the clock frequency FC in proportion to ωT. The pulse period measurement section counts the count clock CLK during τP at the present ω and determines a measured count value C. The feedback filter inputs, as an error signal Ve, the difference between C and a target count value CN that corresponds to ωT, and generates an instruction signal to provide compensation for Ve. The feedback filter scales the instruction signal at a scaling factor that is proportional to ωT.