ELCOM Euro-50, Service Manual

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Euro-50 Service manual
44
Elcom s. r. o.
9 SDCSn-1 CS signal for SD card
10 SDDETECTn-1 Detection of SD card in connector
11 APPDETECTn-1 Detection of power adapter
12 EXT5VON-1 Signal for controlling 5V supply
13 EXT5V 5V
14 EXT5V 5V
15 ONSW-1 Signal for controlling 3.3V supply
5.8. Controlling printing
The Euro 50 uses a LTPZ 245N-C384-E printer.
5.8.1.Supply voltage for the printer
The printer head is powered by voltage VH (6.5 to 8.4V). The logic of the printer is supplied by voltage VDDQSW (3.3V).
Both voltages are switched off when the printer is not in use. Upon switching on, the printer voltage VDDQSW is
switched on first and then VH; the opposite occurs when switching off, according to the specifications. VDDQSW is
switched on / switched off by circuit NL2, which is controlled by microcontroller - signal VDDON. If VDDON = H, then
VDDQSW is switched on. VH is switched on / switched off by the VT1 transistor, which is controlled by the microcon-
troller - signal VHON. If VHON = H, then VH is switched on. The transistor VT3 serves for dissipating the capacity for VH
after it is switched off (VHON = L).
5.8.2. Printer head
Table 5.16. Printer head parameters
Parameter Value
Effective width of printing 48mm
Total number of dots per line 384
Vertical differentiation 8 points / mm
Horizontal differntiation 16 points / mm
Supply voltage Vp 4,2V up to 9.5V
Supply voltage Vdd 3.0V to 3.6V or 4.75V to 5.25V
Top consumption from source Vp 3.6A max. (with Vp = 9.5V) - thermal head 0.6A max. - motor
Top consumption from source Vdd 0,1A max.
Figure 5.1. Block diagrams for the printer head
Grabbing registry
Scrolling registry