Douwe Egberts Cafitesse 100 Service Manual page 146

Service Manual Cafitesse 100
Steps during the dosing process
1. A delivery button is actuated.
2. The water outlet valve opens.
3. The circuit of the concentrate dosing coil is
activated with a delay of approx. 0.3 sec.
The number of pulses to the coil depends
on the ratio (beverage strength) set on the
control board and on the delivery volume.
In order to guarantee a constant beverage
strength, the pulses are emitted at regular
intervals. The 0.3 sec. delay ensures that
water and concentrate are delivered
simultaneously from the trough.
4. The dosing process is completed approx.
0.3 sec. after the water outlet valve has
been closed. Water in the valve outlet hose
bridges the time delay by shortly flushing
the outlet trough.
Ratio (beverage strength)
• The ratio depends on the number of pulses
emitted by the concentrate dosing coil while
the water outlet valve is opened.
• Flow speed:
The dispenser is equipped with a nozzle in the
outlet elbow which limits the flow to 4.5 l/min
(75 cc/sec.).
When it has been programmed with the
Service Device, this value determines the
time for which the valve will be open and
the pulse frequency.
• Number of pulses:
The concentrate : water ratio can be
changed. (see chap. 4)
The delivery volume per pulse is 0.105 cc.
The breaks between the pulses depend on
the flow speed and on the adjusted ratio.
5C - 8
Functions - Dosing System
• Water volume:
The microprocessor calculates the volume
of the delivered water:
Water volume per delivery = volume of the
beverage delivered - concentrate volume
• Empty indicator:
A photodiode and a photo transistor are
attached to the concentrate coil. When
there is concentrate in the dosing tube of
the flexi-pack, the ray of light of the
photodiode is interrupted and the empty
indicator on the switch cover is off.
When there is no concentrate in the dosing
tube, the infrared light arrives at the photo
transistor, the empty indication circuit is
activated and the LED shines.
The sensitivity of the empty indication
circuit must be adjusted on the conrtol
board for coffee or tea concentrate. (see
adjustment)
07.2004