Epson TM-U950 Technical Manual page 86

CONFIDENTIAL
The drawer drive signal is also supplied to the IM-403/405 through CN9 for the TM-U950 only.
DKD1
DKD STAT
DKD POW
DKD2
Figure 2-50a. Drawer Kick-out Circuit for the TM-U950P
Print head drive circuit
The print head has nine pins that are driven by dedicated solenoids. Ports PA0 - PA7 and PB7 of
the gate array carry the solenoid signals (HEAD1 - 9). PB7 carries the common signal for the
solenoids (HD_COM). The HEAD1 - 9 signals activate the sync transistors (QM3 - QM5). The
HD_COM signal activates the source transistors (Q24, Q33, and Q34) to power the solenoids.
When the source transistors go off, the energy stored by the solenoids is dissipated via the
flywheel diodes (D39, D40, D44, D45, D46, and D47). When the sync transistors go off, the
solenoid current is cut.
Rev. A
Figure 2-50. Drawer Kick-out Circuit for the TM-U950
QM1
G-PS24
1
9 8
DKD2
7 6
DKD1
5 4
3 2
CN5 1
0
1 FG
FG 1
2 DKD1
2
D5
3 DK S
3
4 DK P
4
5 DKD2
5
6 SG
D4
SG 6
@ F
G
@
D6
D
{ 24V
K
P
1 2
C9
I O
G
U1 3
{ 5V
Q15
Q7
UNTRG-HIZ
DKD 1 11
R22
10
{ 5V
R9 R8
Q2
DK S 44
DKD 2
R23
Q8
SG
Mechanism Configuration and Operating Principles 2-41
TM-U950/U950P Technical Manual
CPU
PS6
PS7
PE7
Gate array