| 摘要 |
The circuit has a first control FET (15) and second control FET (16). The drain of the first FET has a constant voltage via a first operational amplifier (17) and a control transistor. On the input side it is supplied with a constant reference voltage (Uref). The drain of the second FET is also held at a constant voltage via a second op-amp (19) and control transistor. The arrangement forms a current level of 1:0 ratio. The second control FET functions as a current source and controls the flow of current through the first or second coil (5,7) of the motor. The current from the working voltage (Vdd) flows via a current direction circuit containing the coils . The switching transistors (19-22) are controlled by multiplexers (23-26) which are controlled by a control signal (S). |
