rusefi.com

MHTSOS wrote: ↑

Thu Feb 02, 2023 9:09 pm

The design works but I think that the drawbacks are more that the advantages with the main one being cost savings.
It seems far better to use a "smart" low side driver and have peace of mind.

Yeah, I think something like this is a pretty terrible idea for any standalone ECU.

AndreyB wrote: ↑

Thu Feb 02, 2023 3:51 pm

Things are much nicer this way!

I now have 5v without a lighter, and with a lighter I can get voltage to about 3.7v

You can also try pumping gas from the lighter unlit in to the sensor, that should read even richer than the flame.

Looks like the S+ and S- labels on the PCB are swapped - S+ is really S-, and S- is really S+. Try swapping your sensor wires and see if that helps.

Not to mention that this would set off an EMI bomb if you hit the current limit.

MHTSOS wrote: ↑

Wed Feb 01, 2023 6:42 am

go into its linear region

If there's any inductance in the load (which there is even from a shorted wire), it'll oscillate instead of ending up linear. But still, yes, the dissipation will be significant unless the CPU responds in short order.

So, that's a tight balancing act not in terms of the right injector choice, but rather in the number of available pins on the mcu for FB, and its computational resources (vs using a standalone specialized driver with buil-in bells and whisltes) This circuit also has no clamping mechanism whatsoever.

what is the idea here? these are reverse engineered schematics as an academic pursuit, or these are intended to be built somewhere?

kb1gtt wrote: ↑

Tue Jan 31, 2023 5:27 pm

It's still significant heat to deal with.

0.3 watt is sort of no big deal - a Proteus is about a watt right now, and it barely gets above ambient.

Download a new snapshot rusEFI bundle to get a new version of the simulator and console.

one useful tool is to look at the raw primary vs. secondary in megalogviewer - it looks like you're overtraveling the sensor slightly
try:
set your primary min/max to 0.664/4.340
set your secondary min/max to 4.365/0.671

On the Transistor you use to switch the heater, terminal 2 you should protect it with either a TVS diode or a forward conducting diode to 12v. When the heater is powered and the sensor is suddenly unplugged, there is enough inductance and the currents are high enough that terminal 2 will spike in v...

In the "Nernst Sense" section of the circuit, instead of "LSU_Vm" consider a voltage divider with a voltage set to virtual ground + 0.45 volts. That way you are not amplifying the 0.45v common mode voltage and you can greatly increase the amplification. Because any amount of pre...

Any comments on this schematic https://github.com/rusefi/rusefi-hardware/blob/main/lambda-x2/export/rev0/lambda-x2.pdf ? Planing rev1 with some changes, so review of current schematic will be welcomed. Changes planned to rev1: 1. switch to 64 pin stm32 2. use stm32 DAC (instead of PWM) for current ...

It's not missing!

Upload a log of your issue and tune at rusefi.com/online

https://github.com/mck1117/denso-wideband

Measures -0.8 to +0.8mA, constant 0.4v across the sensor within +-25uV across the current range. Outputs linear voltage from 0.4 to 4.6 volts.

About 70hz -3db bandwidth.

it needs to be hot to work - extremely high impedance when cold

In my case, if you need that tiny bit of fuel for cooling, your engine is so close to the edge you shouldn’t be endurance racing it.

I use it on my racecar. Some napkin math suggested it saves about 1% fuel on track, which is worth half a lap over a stint!

https://rusefi.com/online/view.php?msq=1319&dialog=coastingFuelCutControl

puff wrote: ↑

Fri Nov 25, 2022 9:23 pm

an opamp to amplify voltage?

yes, I did a design a while ago that uses a jellybean dual opamp and some passives. Never fabbed it, though. Will share it if I still have it when back from my trip.

It needs the voltage to be stable, and yet have enough sensitivity to actually measure useful information. The sensor's linearity is only assured when the voltage is stable. 0.36 to 0.50 volts probably doesn't count as stable. You could probably use the sensor if we had the characterization informat...

What do we call those Denso four-wire sensors which are not binary narrow not bosch wideband? planar o2 sensor dron_gus says just a resistor divider and we are in business? What about heater control - is there any strategy or just constant power? Huh? They require current sensing on a constant volt...

Is the idle valve connected to rusEFI? Can you block it off? Some idle valves are partly open when not driven, so as to allow the engine to idle when the wire is broken.

If the idle should be at 1100 there’s nothing you can do with fueling to get to 2700.

Fuel, air, spark. Air should be the same. Fuel doesn’t matter that much. That leaves timing.

What’s your timing like? The stock ecu probably idles at much less than MBT timing.

jabran wrote: ↑

Wed Nov 23, 2022 5:26 pm

I looked in the rusefi console and saw a "warning ignition coil fault" off message but I'm not sure if that is related.

can you copy or screenshot exactly what you saw?

Nissan uses 4 wire "middle band" sensors, I got one to work here: https://rusefi.com/forum/viewtopic.php?p=43610#p43610 do these have anything in common with our WBO logic? Nope, they're basically just "source voltage and measure current" type devices, no active control really n...

preferred method is to upload your tune to rusefi.com/online

https://github.com/rusefi/rusefi/wiki/HOWTO-upload-tune

That scope shot looks fine to me. What does the trigger logger in TunerStudio show?

25kg/h is 7g/s, which is very reasonable for high idle.

You can read airflow over OBD2, right?

It may not be a LSU 4.9. There's a the Denso/NTK equivalent with the same mechanism of action, but different characteristic curve for pump current vs. lambda.