Other Circuits; Fig. 2.32 Power Supply Voltage Checking Circuits; Fig. 2.33 Buzzer Circuit; Fig. 2.34 Drawer Opening Circuit And The Opening Signal Chart - ELCOM Euro-500 Handy Series Service Manual

Euro-500TX Handy

2.3.6 Other circuits

Checking of the accumulator voltage and power supply voltage
The microcontroller detects the internal accumulator voltage using the internal A/D converter through the
resistance voltage divider composed from resistors R56 and R57 (P-LOW signal). Similarly the microcon-
troller checks the connection of the external power adapter through the resistance voltage divider compo-
sed from R32 and R33 resistors (POWER signal).
Buzzer control
The Euro-500TX Handy employs the buzzer to indicate either a pressed key or an ECR error. The buzzer
is controlled by the BUZZER signal via the R42 resistor and T11 transistor.
Drawer opening control circuits
It is possible to connect any ECR drawer to the Euro-500TX Handy that is conformant to the maximum
trigger voltage of 24 V and current of 1.5 A. The drawer will automatically open only if the ECR is connected
to the external power adapter.
DRAWER

Fig. 2.34 Drawer opening circuit and the opening signal chart

The circuit reading the keyboard and JP4 – JP6 jumpers
FD2/RW2
FD3/RW3
FD4/RW4
FD5/JP4
FD6/JP5
FD7/JP6
VCC

Fig. 2.35 The circuit reading the keyboard and jumpers' status

Service manual
VSS
R32
22k/F
POWER
R33
4k7

Fig. 2.32 Power supply voltage checking circuits

BUZ1
1
2
BUZZER

Fig. 2.33 Buzzer circuit

ADP+
D9
LL4148
DRW-
R34
T14
4k7
TIP110
U20
RW2
18 2
1Y1 1A1
RW3
16
4
1Y2 1A2
RW4
14 6
1Y3 1A3
12 8
1Y4 1A4
9 11
2Y1 2A1
7 13
2Y2 2A2
5 15
2Y3 2A3
3 17
2Y4 2A4
RDKEYB
1
1G
20 19
VCC 2G
74HC244
VBAT1
R56
22k/F
P-LOW
R57
4k7
VCC
R42
BUZZER
47k
T15
BC817
ECR drawer opening pulse
U [V]
5
DRAWER
0
50
VCC
R43 R44 R45
47k 47k 47k
© Elcom, s. r. o.
t [ ms ]
JP4
JP5
JP6
Fr 2p Fr 2p Fr 2p
25