Coffee Lack Detection And Coffee Grinder Blocked; Coffee Grinder 120V; Low Bean Level Detection, Dose Quantity Adjustment, Cof - Philips 4000 Service Manual

PHILIPS 4000

3.4.2. Coffee lack detection and coffee grinder blocked

When the coffee grinder is working, the software monitors the current consumption. If the current value is
very low, the machine concludes that coffee is missing; if the current value is very high, the machine concludes
that the coffee grinder is blocked; instead, if the current value is in the middle, the machine concludes that all
is ok and it goes on to do the product.
Because the current consumption of grinder changes depending on the situations (motor new or old, cold or
hot, coffee blends, etc.), these current targets are not static, but dynamic.

3.5. Coffee grinder 120V

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 sen-
sor, which in turn transmits them to the electronic system to grind the correct amount of coffee.
3.6.1. Low bean level detection, dose quantity adjustment, coffee grinder blocked
1
Without beans n=100%
With beans n=100%
Without beans n=50%
With beans n=50%
6
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 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
flavor – mild, medium or strong) and those established by
the softeware.
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.
03 OPERATING LOGIC
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