– 80 –
7. Drive Circuit
Fig. 7-1 shows the drive circuit.
The circuits for U phase, V phase and W
phase have the same Configuration.
●
In low speed rotation mode (PWM range), as shown in Fig. 7-2, 0-5V chopper signal is ouput from microcomputer for each phase. S
ignal
output from microcomputer is ouput to IC1 and is inverted by active Lo to become 0-15V chopper signal; it is then drive the tra
nsistor
of each phase.
●
In high speed rotation mode (PWM range), as shown in Fig. 7-3, 0-5V drive signal is ouput from microcomputer for each phase (wi
th
no chopper because of full duty). Signal output from microcomputer is input to IC1 and is inverted by active Lo to become 0-15V
drive
signal; it is then drive the transistor of each phase.
Fig.. 7-1