Riele Photometer 5010 V5+, Руководство по обслуживанию

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4.40 PCB RR-120 MOTHERBOARD REF 5010-120
Heating
The control variable of the controller has influence on the heating. A switched Darlington transistor in source of
power-switching is used as heating element. The PID-controller produces a voltage at the emitter of the
Darlington transistor by a pulse-width-modulation. This voltage controls the current through the transistor.
Involved components are the microcontroller IC3 (87C52PLCC) and IC7A/IC7B (LM393).
Cooling
For cooling or counter cooling during heating the microcontroller system switches on a Peltier element. There
are four power levels with following terms and meaning:
0 = Cooling out
1 = Cooling (low level)
2 = Cooling (middle level)
3 = Cooling (high level)
In case of temperature changing by method selection cooling level 0 is selected if desired temperature is
higher as selected one.
In case of temperature changing by method selection cooling level 3 is selected if desired temperature is lower
as selected one.
If selected temperature is reached it is switched over to a cooling level depending on the temperature:
•
for 37 degrees Centigrade
⇒
cooling level 1
•
for 30 degrees Centigrade
⇒
cooling level 2
•
for 25 degrees Centigrade
⇒
cooling level 3
The cooling element is a Peltier element. The Peltier element functions as a heat pump and transports heat
out of the cuvette adaptor to the heat sink. The heat sink is provided with air by the fan of the device and
transports the heat outside to the area.
The Peltier element operates with a voltage, switch able on four levels:
•
cooling level 0
⇒
0 V
DC
•
cooling level 1
⇒
0.45 V
DC
•
cooling level 2
⇒
0.9 V
DC
•
cooling level 3
⇒
1.3 V
DC
Involved components are the microcontroller unit IC3 (87C52PLCC), the OP-booster U1A (LM358), the
transistor T4 (BC547), the transistor T5 (TIP132 mounted at the base plate) and the Peltier element.
RIELE BERLIN Photometer 5010 V5+ 4.40.10 17.03.2009