Flow meter fc01-lq – ETA Systems FC01-LQ User Manual
Page 29
Flow Meter FC01-LQ
Flow Meter FC01-LQ
Installation
23
Installation
23
Electromechanical pulse counter (fig. 18)
The FC01-LQ driver output comprises an integral safety circuit which when isolating the counter
operating coil will limit overvoltages caused by inductance and convert the energy stored.
The counter should be able of processing a counting frequency of
≥10 Hz, as the puls e length
is 50 ms (±0.1%) constinuously.
It should therefore be ensured that the counter can be increased by one during the time available.
If a separate relief network is preferred to the integral network, care should be taken when
processing the max. frequency of 10 Hz to ensure the energy stored in the operating coil has
dissipated by the time the counter output is reset. The time to do this should be below 40 ms,
making due consideration to switching times and pulse variations.
Typical circuit (example 2)
Electromechanical pulse counter (fig. 18)
The FC01-LQ driver output comprises an integral safety circuit which when isolating the counter
operating coil will limit overvoltages caused by inductance and convert the energy stored.
The counter should be able of processing a counting frequency of
≥10 Hz, as the puls e length
is 50 ms (±0.1%) constinuously.
It should therefore be ensured that the counter can be increased by one during the time available.
If a separate relief network is preferred to the integral network, care should be taken when
processing the max. frequency of 10 Hz to ensure the energy stored in the operating coil has
dissipated by the time the counter output is reset. The time to do this should be below 40 ms,
making due consideration to switching times and pulse variations.
Typical circuit (example 2)
Note:
❑
As there will be a reset pulse available at the output in the moment the supply voltage of
the FC01-LQ is applied, make sure that the counter is switched on delayed or set to zero
after it has been switched on
XAS
XAO
XAH
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
i
C
U
V
<36 V
Inductance of the
counter drive
i
C
t
L
t
ON
t
U
C
U
V
t
zener voltage
U
C
t
ON
- switch-on time
t
L
- time constent of switch-off current
fig. 18
Note:
❑
As there will be a reset pulse available at the output in the moment the supply voltage of
the FC01-LQ is applied, make sure that the counter is switched on delayed or set to zero
after it has been switched on
XAS
XAO
XAH
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
8
7
6
5
4
3
2
1
i
C
U
V
<36 V
Inductance of the
counter drive
i
C
t
L
t
ON
t
U
C
U
V
t
zener voltage
U
C
t
ON
- switch-on time
t
L
- time constent of switch-off current
fig. 18