obviously 3 wires out of the board are going to 3-wire configuration PT1000
1- 3V3 (RTD 1)
2- B (RTD 2)
3- B (RTD 3)
- Vout is going to MCU ADC
- in second image i attached you can see i have different resistor for op amp gain.
and what I'm thinking of is the following:
1- add capacitor for (B) before the (+) of LM358 to filter noise
2- add 3 TVS diodes to the 3 wires (to GND)
3- add current limiting 10k resistors before the RTD sensor (as shown below) 4- no 10k resistors but add PTC fuse on the 3v3 rail to the sensor to protect shorting?
- is protection with TVS is required actually?
- do you see any flaw or mistake in the circuit, any suggestion is welcomed.
- i don't know if industrial designers protect all inputs/outputs from applying certain level of voltage like +-24v? or it always depend on the project and i don't need to think about it here. so should i think about it here?
- every time the wire length (going to RTD) changes will need to change software compensation variable?
- as you can see I'm simulating the circuit but is't practically going to work efficiently?