COFFEtek BEAN TO CUP, Technical Manual

Page: 13 / 47

COFFEtek LTD
13 01/12/2005 Issue 1 BEAN TO CUP
Circuit Description
27. If the beverage machine is supplied by a 230V single-phase supply from a 10A or 16A
outlet (or from a 13A domestic outlet), only heater 1 can be connected in circuit a 15A fuse
protects the heater circuit, a solid state relay (SSR) contact and high temperature cut-out is
placed in the circuit of heater
28. The SSR switches the supply to the heaters as directed by the MPU Controller in response
to data received from the temperature sensor part of the temperature/level probe, thus
maintaining the water in the boiler at the correct temperature. However, if the water in the
boiler starts to boil, the high temperature cut-outs remove the supply to the heaters. Reset
buttons for cut-out 1 is accessible at the top of the machine.
29. A 230V ac main supply is taken from terminal block to the Power Supply PCB via the on/off
switch. The Power Supply PCB provides DC supplies of 24V, 12V and 5V. The 24V-dc
output supplies the ingredient motors, whipper motors, extract fan, SSR and solenoid
operated valves. The 12V-dc output supplies the MPU Controller Board and operational
coin acceptor (if fitted).
30. The MPU Controller Board continually checks the status of input devices connected to
plugs J1 and J3, and responds to any change of state by signalling the operation of the
relevant output devices via on-board current drive transistors. Thus, for example, the water
level probe controls the operation of the inlet valve and the temperature sensor controls the
operation of the SSR.
31. The dispensing of a beverage begins with the keypad selection, which is scanned by the
MPU Controller Board via a ribbon connector. Control Signals corresponding to the
required actions are then generated by the MPU Controller to operate the relevant output
devices in the correct sequence and for the specified duration. Operator data information is
sent in parallel form to the (LCD) Display.