Air Fuel ratio sensor LSU 4.9 sensors interfacing (oxygen sensor)

[aliraza786]

Air Fuel ratio sensor LSU 4.9 sensor interfacing ( oxygen sensor )

air fuel ratio sensor used in cars, model LSU 4.9 boash , controller Chip CJ125 , i have searched alot, lots of info is also available but till now i am not able to understand its basic working principle of this sensor, because i want to use this sensor without the Controller chip, i want 0 to 5 volt output but CJ125 gives data in SPI format.
also i am confused in functions of different pin out of this sensor.

Kindly help
ali

 

[dick_freebird]

Re: Air Fuel ratio sensor LSU 4.9 sensor interfacing ( oxygen sensor )

(1) Do you care about operating away from stoichiometric?
If no, then a simpler sensor and A=5 single supply op amp
is your ticket.

(2) I expect Bosch has some app notes about LSU4 sensors
and their care / feeding. This is not trivial, controlling the
element temperature is key and behind that I'm sure is a
cal-map of some sort.

(3) You would probably be effort and money ahead, to use
something like the NAW kits. I got one some years back and
found it way, way cheaper than my Innovate LM-1 wideband
meter.

I'd start with drilling into Bosch sensor collateral literature
as deep as you can, if you mean to cobble something on
your own.

 

[aliraza786]

Re: Air Fuel ratio sensor LSU 4.9 sensor interfacing ( oxygen sensor )

Hello Dick_dick_freebird thanks for the detailed reply i am just interested in is if i control the temperature by some means then i just want to measure the oxygen content in the exhaust gases. i dnt remember exactly as what is stoichiometric is , but if the pump current is referring to the oxygen content in the exahust gase then i can use opamp to amplifier it, i need little more info about its connection, like which pin of sensor should be connected to which pin of opamp.

Thanks alot for you guidance.

Kind Regards
Ali

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Like in this image , shown a pinouts of LSU 4.9
https://www.google.com.pk/search?q=...Pro0b3nxwIVglwaCh112wyu#imgrc=4ockqAKbUlaX4M:

This which pins should be connected to which pins of opamp.

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are you suggesting me something like this ?