5999.505-01C 12.06.2007 WM
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Technical description
5.1
Dispenser board
All the electronic devices including power transformer, except of the main
switch with indicator lamp, are located on a printed board. The dimensions of
the board are approximately 215 x 234 mm. Figure 8 shows the board with
all the connectors and terminals.
The description is divided into power supply, motordriver, controller and firm-
ware.
5.1.1
Power supply
The power supply unit generates the two regulated vo12 V/1A and +
5 V/0.5A for the logic, as well as an unregulated DC voltage of approx. 32 V/
3.5 A for the steppermotor. The 5V stabilization is done by linear voltage reg-
ulators. The 12V is stabilized by a switched mode regulator.
5.1.2
Motordriver
The driver board consists of 2 H-bridge circuits to drive the two motor phases.
The phase current is 3 A while running, and 0.7 A when stopped. To control
the current, a chopper circuit with 23 kHz chopper-frequency is used.
Dependent on the dispensing speed the processor generates a sinusoidal
current.
In the case of overheating, short-circuit or malfunction the motordriver is swit-
ched off. In this case the labeler must be switched off and on again. If over-
heated wait until the labeler is cooled down to ambient temperature. After a
short circuit replace the appropriate fuses.
5.1.3
Controller
A single chip micro-controller manages the functions of the labelling process.
•
All the inputs are pulled up to +12V with 2.2 K and are equipped with a low-
pass filter.
•
The potentiometers for speed and predispensing are scanned immediate-
ly before performing a labeling cycle.
•
The control current of the label scanner is generated by a current source
controlled by the thirt potentiometer.
