Service manual

18 TTPM3 - Service Manual March 2009
3.3.7 Power supply
The power supply unit (PSU) is of the switched mode type and supplies +24V to
the control board.
A transistor on the control board switches ON the +24 V when motors, solenoids
and printhead is to be used and keeps it off when the printer is idle. This is to
prevent the drive circuits in the printhead from becoming damaged since their
status is undefined before the +5 V is at correct level.
NOTE! — At these high currents it is essential that the leads and connectors be in
good condition. Excessive resistance in these parts may cause very
strange behavior of the printer.
With Zebra power supplies, just connect the cable from the power supply to J5.
If you use another type of power supply unit, 24 V cables are available from Zebra,
order No. 01370-000.
Should you make cables of your own, connect the voltages according to the
following illustration. Note that protective ground and minus output should not be
interconnected in the power supply. At the printer end of the cable, use an AMP
Mate-N-Lok connector housing and two contact-sockets:
Housing: AMP No. 350777-1
GND
+24 V
Socket: AMP No. 350689-1
Figure 11. Power connection
Mode
Idle
150 mA
Standard text printing
2 A
average
Peak current
6 A
Table 1. Current consumption
NOTE! – The 24 V ground, as well as the chassis of the printer, must be connected to ground
potential (safety ground).