Resistance-to-current transmitter with galvanic isolation between the input and output of the thermocoupler

Term paper in electronics on the topic "Measuring resistance to current   converter with galvanic isolation between the input and output of the resistance thermocoupler pt 50 at a temperature of 0-200 °C  and the presence of an alarm". The work includes a set of drawings (structural diagram and electrical and circuit diagram) and a calculation and explanatory note.

1 Technical data

1.1 Input Circuit

1.1.1 Number of inputs: 1 pc

1.1.2 Type connected to the RI converter: TC resistance thermocouple, Pt 50.

1.1.3 Measured temperature range: 0-200 oC.   

1.1.4 Connection diagram of the resistance thermocouple: three-wire.

1.1.5 Length of the communication line between the RI transducer and the resistance thermocouple: not more than 300 m.

1.1.6 Resistance of one wire: not more than 15 ohms.

1.1.7 Maximum resistance difference of communication line wires: not more than  0.1 Ohm.

1.2 Exits

1.2.1 Number of analog outputs: 1 pc

1.2.2 Output range: 4 to 20 mA

1.2.3 Analog output load resistance: not more than 500 ohms.

1.2.4 Number of discrete outputs: 2 pcs

1.2.5 Discrete Output Parameters:

– switching voltage : no more than 220 V;

– switching current: no more than 0.5 A.

1.3. Limits of permissible reduced basic error of resistance to current conversion: ±0.5 %.

1.4 Mains voltage: AC from 20.4 to 26.4 V with a frequency of 49 to 51 Hz.

1.5 Power consumption: not more than 6 V∙A.

1.6 Maximum and minimum setpoints: yes.

1.6.1 Explosion protection: none.