Oki Microline 3320

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2.1.6 SP/LF Motor Control
(1) Space motor control
The SP motor driver (HA13412) drives the three-phase brushless motor based on the
phase signal (SPU, SPV and SPW) and the speed instruction data from the LSI. The MPU
can identify the current speed of the space motor by measuring through the LSI the pulse
length of the output (øA, øB) of the slit encoder included in the space motor.
By comparing the target speed for each print mode with the actual current speed to change
the speed instruction data, the motor speed is accelerated or decelerated to maintain the
specified speed for each print mode.
SP truth table
HALL AMP INPUT OUTPUT
SPU SPV SPW U V W
H H L OPEN L H
H L L L OPEN H
H L H L H OPEN
L L H OPEN H L
L H H H OPEN L
L H L H L OPEN
SPU
SPV
SPW