Flow vision FC 01- CA User Manual page 32

Flow Meter | FC01- CA
Electromechanical pulse counter (fig. 22)
The FC01-CA 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 pulse length is
50 ms (±1%) continuously.
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 dis-
sipated by the time the counter output is switched on again. The time to do this should be below 40
ms, making due consideration to switching times and pulse variations.
Typical circuit (example 2)
XAS
1 2 3 4
t - switch-on time
ON
t - time-constant of switch-off time
L
Note:
q
As there will be a reset pulse available at the output in the moment the supply voltage of the
FC01-CA is applied, make sure that the counter is switched on delayed or set to zero after it
has been switched on.
32
INSTALLATION
XAO
5 6 7 8 1 2 3 4 5 6
INSTALLATION
XAH
7 8 1 2 3 4 5 6 7 8
i
C U
C
U
V
t t t
L ON
inductance of the
counter drive
zener voltage
t
fig. 22