A little help how to convert HIH-4000 voltage output to current output 4-20mA, maybe with LM317 (something like you can find about temperature sensor LM35 and LM317 in LM35 datasheet) or you have better suggestion, I'm stuck
You have an humidity sensor. You also mention temperature sensors and one well known voltage regulator. Can you clarify your own ideas first and them come back with a more clear question?
OK, here's what I need:
humidity sensor with HIH-4000 with current output 4-20mA
I mentioned temp sensor LM35 with current output 4-20mA and it's done with LM317 and it works well, so I mean somebody made something similar for humidity sensor HIH-4000, that's the reason for mentioning LM317...
Thanks a lot, I'll try it immediately and let you know...
Also, maybe you have solution with LM317, like in PDF for LM35 and here's schematic:
HIH-4000 instead LM35?, but I couldn't find more details about this schematic and I made it and it works well for temperature.
I didn't have CA3240 (instead 2xCA3140) and I used TL072 for test and it works well!
Just one more question about calibration, I mean, how to set output current exactly from 4-20mA, can I replace 250ohm on emitter with trimmer to adjust output current?
I didn't have CA3240 (instead 2xCA3140) and I used TL072 for test and it works well!
Just one more question about calibration, I mean, how to set output current exactly from 4-20mA, can I replace 250ohm on emitter with trimmer to adjust output current?
I've done that, but, at the end, I used 56ohm and 50ohm multiturn trimmer to get "real" value and also, I'm planning to go to meteo station to compare results with their RH sensors
One more thing, can you, please, tell me in which software you done simulation and can you send me file to try myself? I suppose it will help me to better understand whole circuit.
I've done that, but, at the end, I used 56ohm and 50ohm multiturn trimmer to get "real" value and also, I'm planning to go to meteo station to compare results with their RH sensors
One more thing, can you, please, tell me in which software you done simulation and can you send me file to try myself? I suppose it will help me to better understand whole circuit.