Saeco Xsmall Plus, Service Manual, Page: 21 / 42

Saeco Int. Rev. 00 / Jul. 2008 Page 5 / 6
XSMALL 04 OPERATING LOGIC
4.6. Coffee grinder function
Ceramic 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 transmit two pulses to a
Hall sensor, which in turn transmits them to the
electronic system.
2
3
4
5
6
1
4.7. Low bean level detection, dose quantity adjustment, coffee grinder
blocked
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 performed at
the end of each grinding process.
Dose quantity adjustment
The dose quantity is adjusted in accordance
with the pulses detected (number of rotations
proportional to the selected fl avour - mild,
medium or strong).
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.
Without beans n=100%
With beans n=100%
Without beans n=50%
With beans n=50%