2. Working principle: there are two light emission fluorescent tubes on top of the opening of slot-in
loader disk and there are two photoelectric tubes at bottom on two ends of disc opening. After loading a
disk, the disk holds up the light emitted from light emission tube to make the corresponding photoelectric
Diode (Q2) of this light emission tube cannot receive lights. Detect signal DISCEJT on loader outputs
high level to decode board. When DISCEJT pin of Mt1389 detects that DISCEJT signal is high level,
output disc tray in control signal. After disc tray enters to proper position, mechanical structure of loader
touches disc tray in switch, TRIN becomes high level from low level, decode chip stops outputting disc
tray in signals and machine begins to read disc. When disc tray is out, transmission structure conveys
disc outwards. When disc passes through the detecting of the photoelectric tube (Q1) inside loader,after
disc is out to the appointed position, TROUT becomes low level and disc tray out stops.
Note: in order to understand more simply, this schematic diagram has some difference from real
circuit, so please note.
3.2.6 Disc in/out circuit
1. Disc in/out circuit is shown as the following figure 3.2.6.1:
- 85 -
Figure 3.2.6.1 Disc in/out circuit diagram
R465
100R
R469
470R
Q130
8050D
Q129
8050D
Q127
8550D
Q128
8550D
R198
220R
R195
220R
R196
10K
R197
2.2R\1/4W
CE168
47uF/16V
CE169
47uF/16V
LOAD+
LOAD-
+5V
TRCLOSE
Q180
9014-S
TROPEN
TROPEN
MT1389
2. Working principle: INDISC, OUTDISI are disc in/out control signals and are connected to pin 39,
54 of U201 (MT1389) respectively. LOAD+, LOAD- connect with two ends of electric machine to control.
When users are performing disc out operation, servo control chip U201 (MT1389) sends out control
signal through pin 39, 54 and changes level of LOAD+, LOAD- to change the rotation direction of electric