Mipex MIPEX-02 1 Series, Руководство пользователя

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OPTOSENSE LLC
Design Department
USER MANUAL
SMALL-SIZE EXPLOSIVE GAS MEASURING SENSOR MIPEX-02-
Х-X-X.1 X
File name: ESAT.413347.006 UM v.2.0.docx Revision 2.0 27 August 2015 Page. 22 of 38
THE SOLE PROPERTY OF OPTOSENSE LLC. ANY REPRODUCTION WITHOUT THE WRITTEN PERMISSION OF OPTOSENSE LLC IS PROHIBITED.
Fig. 7. Example of connecting sensor
to “ia” intrinsic safety circuit.
Fig. 8 demonstrates the waveforms of typical MIPEX-02 current consumption and barrier voltage drop with the different values of R. If
capacitor C = 20uF and resistor R = 30Ohm in power supply part of the diagram in Fig. 1, the output voltage of the barrier during the current
pulses are not less than 3.1V, then MIPEX will work properly (without negative influence on performance ). If capacitor C = 20uF and resistor R
= 60 Ohm, the barrier output voltage falls below the minimum supply voltage 3.0V. In this case, the sensor might be unstable.
To prevent MIPEX-02 supply voltage decrease below 3.0V, use following recommendations:

Increasing of barrier supply voltage.

Increase the value of the capacitor in line: i.e. for R = 60 Ohm use capacitor value at least C (uF)~ 2/3 * 60 (Ohm) = 40 uF.

Reduce the value of R (but not less than 25 Ohm, because of limitations Ui=0,25W with 5Vmax).