1
2
T
3
CH1!5 . 00 V=
CH2!5 . 00 V=
C H 3!5 . 00 V= 4
CH4!5 . 00 V=
P M 3 3 9 4 , F L U K E & P H I L I P S

Sled Stepping Motor

 

Name

Location

Voltage/div

 

 

 

 

Channel 1

STVC (ref)

IC701/pin 7

2Vp-p

 

 

 

 

Channel 2

SLDA (inward)

IC701/pin 9

2Vp-p

 

 

 

 

Channel 3

SLDB (outward)

IC701/pin 8

2Vp-p

 

 

 

 

Time base

 

5usec/div.

 

 

 

 

 

The sled motor can be driven manually in either direction to produce the waveforms shown by using the test mode’s manual servo control.

Sled Driver IC802 Sends Voltages to the Stepper Sled Motor

When the input pulses to pulse Sled motor Driver IC802 are not identical to the input reference, the sled motor is driven. At the output, if pulses to the B coil of the stepper type sled motor are lower than the pulses applied to the A coil, the sled moves the laser outward. This can be seen in the waveforms taken at IC802’s output.

Sled Motor Waveforms

All four sled motor drive signals in these waveforms show that the B coil of the stepper motor gets a reduced amplitude pulse to move the laser as- sembly outward.

ch1

ch2

ch3

ch4

STOP

CHP MTB50 . 0ms - 1 . 34dv ch3 -

Outward Sled Drive Waveforms

 

Name

Location

Voltage/div

 

 

 

 

Channel 1

B coil -

CN003/pin 11

5Vp-p

 

 

 

 

Channel 2

B coil +

CN003/pin 8

5Vp-p

 

 

 

 

Channel 3

A coil -

CN003/pin 7

5Vp-p

 

 

 

 

Channel 4

A coil +

CN003/pin 9

5Vp-p

 

 

 

 

Time base

 

50msec/div.

 

 

 

 

 

45

Sled Drive Mute/Inhibit

The sled and loading motors are inhibited when the tray is out. IC601 performs this operation by grounding IC802/pin 9 to stop the driver IC802.

Driver IC 802/pin 9 Mute/Inhibit

IC802/pin 9 Voltage

Mode

 

 

2.3V = normal operation

Tray closed

 

 

0V = tray loading and sled motors inhibited

Tray open

 

 

Home Position Detection

The laser assembly’s home position is identified by a in-limit photodetec- tor within the assembly. The photodetector consists of an IR LED and a photo transistor. Light from the LED passes through an open area to turn on the phototransistor, placing CN003/pin 11 at ground level. When the laser assembly arrives at home position, it blocks the light, permit- ting IC701/pin 23 to go high. IC701 relays this information to Syscon IC201, via IC601 and home is identified.

The verification of this detector is important to determine if IC202 can complete the initial check sequence and remain powered ON.

1.Place the unit in the special test mode (From power OFF, Press front panel buttons RETURN and STOP together. Press MENU on the remote. The unit will power up if IC201 and the power supply are OK).

2.Measure the voltage at MB-85 board, CN003/pin 11.

·3V = Laser at home (by the spindle motor)

·0V = Laser away from home

3.You can manually push the metal laser base to slide the laser.

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Sony S530D Home Position Detection, Sled Driver IC802 Sends Voltages to the Stepper Sled Motor, Sled Drive Mute/Inhibit