Philips Saeco Royal HD8838, Service Manual

Page: 23 / 52

SYNTIA CAPPUCCINO 04 OPERATING LOGIC
Saeco International Group Page / 08
4.7. Coffee grinder
2
3
4
5
6
1
4.8. Detection of coffee bean absence, dose adjustment,
blocked coffee grinder
t1
V
t2
t3
t4
t
Without beans n=100%
With beans n=100%
Without beans n=50%
With beans n=50%
The coffee grinder is activated by a direct current motor (1) via helicoidal wheel transmission and
a worm screw (2).
The worm screw (2) activates a plastic toothed wheel (3), which turns the lower grinder blade (4)
and the increment pin (5)
There are two magnets (6) in the toothed wheel and with every rotation they transmit two pulses
to a Hall sensor, which in turn transmits them to the electronic system.
No coffee
When no coffee beans are present, this is detected by the Hall
sensor due to 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 there are coffee beans, the number of rotations will be lower
due to the force created during the grinding process.
t2 = no indication
t3 and t4 = this reading is taken 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 weak, medium and
strong flavour selection).
Blocked grinder blades
If the coffee grinder is blocked for any reason, pulses will no
longer be transmitted to the electronic system and the grinder
stops.
05