Star Micronics SP500 Series User Manual page 119

Drive circuit
The recommended drive unit is shown below.
F.G
TR1
M-GND
TR2
M-GND
+5V
TR3
Notes
• Peripheral Units 1 and 2 cannot be driven simultaneously.
• For continuous driving, do not use drive duty greater than 20%.
• The status of the compulsion switch can be known from the following.
Star mode
ESC/POS mode : The status of the compulsion switch can be known by using
Parallel interface : The status of the compulsion switch can be known by pin
• Minimum resistance for coils L1 and L2 is 24Ω.
• Absolute maximum ratings for diodes D1 and D2 (Ta = 25°C) are:
Average Rectified Current Io = 1A
• Absolute maximum rating for transistors TR1 and TR2 (Ta = 25°C) are:
Collector current Ic = 2A
Collector loss Pc = 1.2W
D1
7824
+24V
D2
R1
R2
Printer side
: The status of the compulsion switch can be known by using
the automatic status function or <ENQ> commands. In the
case of ENQ status, bit 7 will be "1"when pin No. 6 of the
peripheral unit drive circuit is high (switch on).
the automatic status function, <DLE><EOT>n, and
<ESC>"u"n commands.
No. 34 on the parallel interface connector. When the
compulsion switch is on, pin No. 34 will be low. This can
be checked by using the compatibility mode.
– 116 –
1
With shield
2
L1
3
4
L2
5
Peripheral
unit 2
6
Frame
ground
User side
Peripheral
unit 1
R3
4.7kΩ
1/4W
Compulsion
switch