Coffee Grinder; Low Bean Level Detection, Dose Quantity Adjustment, Coffee Grinder Blocked - Philips Saeco Exprelia Series Service Manual

EXPRELIA
4.7.

Coffee grinder

The coffee grinder is driven by a direct current motor (1) using a worm screw helicoidal wheel
transmission (2).
The worm screw (2) drives a plastic gear wheel (3), which turns the lower grinder (4) and the
increment pin (5)
There are two magnets (6) in the gear wheel; at every rotation these induce two pulses to a Hall
sensor, which in turn transmits them to the electronic system.
4.8. Low bean level detection, dose quantity adjustment, coffee grinder
blocked
Without beans n=100%
t1
V
t2
t3
t4
Saeco International Group
6
1
With beans n=100%
Without beans n=50%
With beans n=50%
t
3
No coffee
A low coffee bean level is detected by the Hall sensor,
after variations in the pulse frequency (with or without
coffee).
If there are no coffee beans (operation while empty),
the number of rotations – and therefore the number of
pulses – will be greater
t1 = no coffee indication
If, however, there are coffee beans, the number of rotations
will be lower due to the force created by the grinding
t2 = no indication
t3 and t4 = this measurement is taken at the end of
each grinding cycle
Dose quantity adjustment
The dose quantity is adjusted in accordance with the
pulses detected (number of rotations proportional to the
weak/medium/strong aroma setting)
Coffee grinder blockage
If the coffee grinder becomes blocked for any reason,
pulses will no longer be transmitted to the electronic
system and the grinder will come to a stop
Rev. 00 / June 2010
04 OPERATING LOGIC
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