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KE Jetronic
Posted: 02 Mar 2023 17:40
by Cauf61
Hello
I am interested in your Lambda shield 2 set. I assume I can use it to convert a wide band lambda input signal to a narrow band signal for my KE Jetronic. I shall need to build a PWM RC filter/output buffer because I don’t know the current (impedance) a KE Jetronic draws.
But, would it be possible to adapt the output to a plus or minus 10% level ?
I have some arduino skills.
Grts
Patrick
Antwerp
Re: KE Jetronic
Posted: 03 Mar 2023 04:37
by Christian_Bylund
Hello Patrick,
Cauf61 wrote: ↑02 Mar 2023 17:40
I am interested in your Lambda shield 2 set. I assume I can use it to convert a wide band lambda input signal to a narrow band signal for my KE Jetronic. I shall need to build a PWM RC filter/output buffer because I don’t know the current (impedance) a KE Jetronic draws.
Unfortunately I have no knowledge of the lambda input of KE Jetronic. In
this video we use a Lambda Shield and Arduino Uno to generate a narrowband signal for a lambda gauge. For Lambda Shield 2 it is recommended to use the Arduino Mega,
see more here.
Cauf61 wrote: ↑02 Mar 2023 17:40
But, would it be possible to adapt the output to a plus or minus 10% level ? I have some arduino skills.
Yes, simply adjust the output conversion from wideband to narrowband in
Lambda_Shield_2_Example.ino
Code: Select all
//Displays the AFR value on an external narrowband lambda gauge with an (RC-filtered) 0-1V PWM signal from ANALOG_OUTPUT_PIN. 0V = AFR 20.00. 1V = AFR 10.00.
void UpdateAnalogOutput() {
//Local constants.
const float AirFuelRatioOctane = 14.70;
const int maximumOutput = 51; /* 1V */
const int minimumOutput = 0; /* 0V */
//Local variables.
int analogOutput = 0;
float lambdaAFR = Lookup_Lambda(adcValue_UA) * AirFuelRatioOctane;
//Convert lambda value to PWM output.
analogOutput = map(lambdaAFR * 100, 2000, 1000, minimumOutput, maximumOutput);
//Make sure we do not exceed maximum values.
if (analogOutput > maximumOutput) analogOutput = maximumOutput;
if (analogOutput < minimumOutput) analogOutput = minimumOutput;
//Set PWM output.
analogWrite(ANALOG_OUTPUT_PIN, analogOutput);
}
Hope it helps.
Re: KE Jetronic
Posted: 03 Mar 2023 20:14
by Cauf61
Thank you very much.
I will order a set (but with wifi)
Could you give as example a -10% conversion factor (so as result 10% leaner mixture) please ?
As said I will make a RCfilter/buffer capable of max 500mA narrowband signal out , so I think that will be more than enough for the KE Jetronic
Grts
Patrick
Re: KE Jetronic
Posted: 04 Mar 2023 20:35
by Cauf61
Hello Christian.
I am looking a bit deeper in to the matter. Am I wrong or is the shield giving out a linear 0-1V signal out in your AFR meter video ? This is not a narrow band simulation, no ? A narrow band signal goes from +- 0,1 to 1V with a very steep angle between 400 to 500 mV. (14,7 R)
Grts Patrick
Re: KE Jetronic
Posted: 07 Mar 2023 17:20
by Christian_Bylund
Hi Patrick,
Cauf61 wrote: ↑03 Mar 2023 20:14
As said I will make a RCfilter/buffer capable of max 500mA narrowband signal out , so I think that will be more than enough for the KE Jetronic
The maximum current you can draw from a nernst cell is in the μA range. But again, I do not know what kind of input the KE Jetronic use or if it is some amplified circuitry.
Cauf61 wrote: ↑04 Mar 2023 20:35
Could you give as example a -10% conversion factor (so as result 10% leaner mixture) please ?
I am looking a bit deeper in to the matter. Am I wrong or is the shield giving out a linear 0-1V signal out in your AFR meter video ? This is not a narrow band simulation, no ? A narrow band signal goes from +- 0,1 to 1V with a very steep angle between 400 to 500 mV. (14,7 R)
Do you want it to be ±10% lambda 1? You are correct, a narrowband signal is exponential. The example is a simplified linear output for lambda gauges.
Re: KE Jetronic
Posted: 07 Mar 2023 19:35
by Cauf61
Hello Christian
Do you want it to be ±10% lambda 1?
Yes, as example.
The example is a simplified linear output for lambda gauges
But the shield can reproduce a real narrow band signal from the WB 4,9 LSU ?
Re: KE Jetronic
Posted: 08 Mar 2023 19:43
by Cauf61
Hello Christian
Can the shield reproduce a real (exponential at +- 450mV ) narrow band signal from the WB 4,9 LSU ?
Grts
Patrick
Re: KE Jetronic
Posted: 12 Mar 2023 15:26
by Cauf61
So I guess not.
Ok.
Re: KE Jetronic
Posted: 12 Mar 2023 15:33
by Christian_Bylund
Cauf61 wrote: ↑08 Mar 2023 19:43
Can the shield reproduce a real (exponential at +- 450mV ) narrow band signal from the WB 4,9 LSU ?
The shield no, the Arduino yes. The lambda shield measures a wideband sensor that the Arduino can use for any purpose.
Re: KE Jetronic
Posted: 12 Mar 2023 20:44
by Cauf61
Dear Christian,
I assume you program the "exponential" NB curve in the arduino lookup table itself ?
The values, you calculate in excell or so ?
Like I said i would like to buy the "wifi" kit, but I have to be certain that I have the possibility to trick the ECU (now running on a NB) to run richer of leaner.
I know, leaner is very dangerous. :-)