lambda probe interface IC - CJ125 from Bosch

[almarto]

Dear all,

Is there anybody who has used this IC from Bosch Semiconductors to control air-fuel ration in gasoline engines? I have great interest in engaging technical discussions about it.

I am using both CJ120 and CJ125.

Best regards.

[ko4ko]

I try to measure with CJ120 bosch ic , but have some problems with RI measuring. Can U help me
Thanks in advance!

[almarto]

Hi ko4ko,

I am beginning with my project right now since I have been collecting information these last months. I come back to this post in a few days and I will comment with you how are things going. I have found a great drawback due to the lack of information by Bosch. Can you please send me any datasheet you have? I will do the same with my information. My e-mail is [email protected].

Best regards.

[ko4ko]

I'll tell with some words what I did:
LSU that I use is BOSCH...7057, IC - BOSCH CJ125 , I made a demo board with the connection exactly the same as in the CJ125 description. I use pic mcu to control the bosch ic . there are 2 analog values to measure , measuring RI is needed to control the heater.
Did U make any board with bosch IC ? , and did U succeded with measuring AFR. Aaa now I have available one working LSU controller - WBO2.
I think to compare it with mine on working car , but .....it's harder than I think to make it work properly.
The other thing that I can't understand is how to transformate the measured value /voltage 0-5V/ to AFR/ 8.0 - 18.0/

[Joco]

Where did you find CJ125 IC?

[john micheli]

I'll tell with some words what I did:
LSU that I use is BOSCH...7057, IC - BOSCH CJ125 , I made a demo board with the connection exactly the same as in the CJ125 description. I use pic mcu to control the bosch ic . there are 2 analog values to measure , measuring RI is needed to control the heater.
Did U make any board with bosch IC ? , and did U succeded with measuring AFR. Aaa now I have available one working LSU controller - WBO2.
I think to compare it with mine on working car , but .....it's harder than I think to make it work properly.
The other thing that I can't understand is how to transformate the measured value /voltage 0-5V/ to AFR/ 8.0 - 18.0/

i have several air fule meters i could match up what you did if it is simple to do. played with the bosch part back in 2003 but gave up due to bosch refusing to give up useful information. my demo board is still around here so maby i could re visit it again. every once in a while i re visit the dame thing.
regards
john m.

[ko4ko]

first excuse me for my bad English.
my exact question is about calculation of AFR. Now I'm measuring some voltage from cj125 , but I can't find anywhere formula to take the AFR from this voltage? Can U help me ?
Best regards!
Ko4ko

[john micheli]

Hi ko4ko,

I am beginning with my project right now since I have been collecting information these last months. I come back to this post in a few days and I will comment with you how are things going. I have found a great drawback due to the lack of information by Bosch. Can you please send me any datasheet you have? I will do the same with my information. My e-mail is [email protected].

Best regards.

tried to get information from bosch; they are very hard to pull info from. havnt tried in 18 months tho. have a few parts but the data sheet is bad.
regards
john m.

[peco]

hello,

I am also interested in making such an interface. I am not so good in electronics as I am started with it a few months ago. I don't understand what I got to do with the SPI interface. What signal gives the microcontroller to the SPI interface?

thanks
pedro

[Ben_pvbj]

Hi all here
now I am to complete the oxygen percent measurement employing the cj120 chip . I notice that in its CJ120_Product_Info the chip present volt UR to calculate the internal Ri basing on the Rcal about 82.5 ohm , but I dont know how to get the precise value of Ri, is there any famulation about that? I made the Ri always arroud 120 ohm , it couldn't reach the value 80 of 780 .

another question is how to use the UA to calculate the lambda value , I made the Ip value with the equation Ip=(UA-1.50)/(61.9*17) but how do I get the lambda value , looking up the table ,but where to get the lambda-IP table? Or is there any other ways to get the lambda because I noticed that they present a formulation between the XO2 % and the lambda =(XO2 /3+1)/(1-4.76*XO2 ).

[gastonrey]

Hello Everyone.
I landed on this forum serching for information about the CJ-125
I have purchased 8 of them last month from BOSCH and I'm experimenting with them.
If anyone is interested I will have 7 for sale, ince I don't need all of them.
They are new.

I'll post some good diagrams and tech support pdf files later on today.

Regards.
Gaston
[email protected]

[wbjunkie]

I have been hunting for the CJ125 for ages.
How the hell do you get your hands on this.
Why do they make it so hard ?

[Archangel]

2 min on Google.
http://www.futureelectronics.com/en/...spx?CrossPart=
Looks like Future is your best bet for this part, The US Distributor appears only to sell Complete Units here is their link:http://www.chiefenterprises.com/dnn/
I have a hunch this is the chip used in their Hot Film Mass Airflow Sensors, here is a link to the sensor page of their website.
http://rb-k.bosch.de/en/powerconsump...ement/hfm.html