| 摘要 |
PURPOSE:To need no speed detector by controlling the frequency and phase of electrification switching signal, according to the phase difference of counter- electromotive voltage generated on motor driving coils under electrification quiescence, and the electrification switching signal, and dy composing a phase controlling loop. CONSTITUTION:With the signal D1 of the output (f) of a voltage controlling oscillator 40 with divided frequency 41, via the logic circuit 42 and the power amplifier 43 of an electrification switching circuit 44, driving transistors Tr 10-15 are controlled, and driving coils 1-3 are driven in constant phase relation to the output (f), and counter-electromotive voltage in the constant phase relation is generated. With frequency-dividing signal D2 and the output amounts U1-W2 of the logic circuit 42, phase difference detecting pulse is generated, and a phase error between coil voltage U0-W0 and the counter-electromotive voltage is detected, and the error is amplified 30, and is fed back to the voltage controlling oscillation 40, and a phase controlling loop is composed. As a result, a circuit for requiring no rotation detector is composed, and the output of exact speed signal is quickly generated. |
