Omega Speaker Systems OME-DB-889D manual Open Thermocouple Detection

4.4 Open Thermocouple Detection

The OME-DB-889D provides open thermocouple detection through a resistor circuitry. These resisters are normally not connected. The user can find on the back of the board has two solder gaps for each input channel. If you short the solder gaps, the open thermocouple detection is enabled.

Channel 0 High

Channel 0 Low

HJ0 100MΩ

-15V

1.2KΩ

1uF 50V

1.2KΩ

OME-DB-889

37Pin Cable GND

LJ0 10KΩ

Note:

If a thermocouple opens, the bias resistor will slowly pull the input voltage to -10V then user can use a simple application program to detect the voltage change.

OME-DB-889D User’s Manual 18