Gaggia Brera Service Manual

Also see for Brera: Operating instructions Operating instructions Manual Operating instructions Operating instructions

Rev. 00 OCTOBER 2009 Page / 06GAGGIA 04 OPERATING LOGIC4.6. Coffee grinder operation2345614.7. Low bean level detection, dose quantity adjustment,coffee grinder blockedt1Vt2t3t4tWithout beans n=100%With beans n=100%Without beans n=50%With beans n=50%Ceramic coffee grinderThe coffee grinder is driven by a direct current motor (1) using a worm screw helicoidal wheeltransmission (2).The worm screw (2) drives a plastic gear wheel (3), which turns the lower grinder (4) and theincrement pin (5).There are two magnets (6) in the gear wheel; at every rotation these induce two pulses to a Hallsensor, which in turn transmits them to the electronic system.No coffeeA low coffee bean level is detected by the Hall sensor, aftervariations 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 ofpulses - will be greatert1 = no coffee indicationIf, however, there are coffee beans, the number of rota-tions will be lower due to the force created by the grindingt2 = no indicationt3 and t4 = this measurement is taken at the end ofeach grinding cycleDose quantity adjustmentThe dose quantity is adjusted in accordance with thepulses detected (number of rotations proportional to theweak/medium/strong aroma setting)Coffee grinder blockageIf the coffee grinder becomes blocked for any reason,pulses will no longer be transmitted to the electronicsystem and the grinder will come to a stop05