Project JAGuar for FreeEMS

[DeuceEFI]

Crankshaft and Camshaft Position Sensor information:

Both are Hall Effect Sensors, the signals are digital HI/LO and I have attached the graph of the output signals over a complete firing order cycle.

Andy

[Fred]

Just to get this in quickly, and not having had time to reply to the previous posts, but although you CAN use a normal logic buffer for digital inputs, you're better off using a schmidtt trigger for noise immunity, consider this. Also, if you use the max9924/6 chips, you have the option of going VR later, though they are significantly more expensive than a normal IC.

For digital inputs you want 1k (or maybe lower) pull up and a small cap as well. This provides more noise immunity at the expense of top end frequency RPM, but if you size it right, it's got a negligible negative effect in the range that you need. This is assuming an open collector style drive, which is the norm with most of this stuff.

More later!

Fred.

[Fred]

The FETs I chose for the injectors were originally what I pulled out of the GM ECU, manufacturer unknown and I haven't been able to cross reference the markings "435M9395" on DPAK footprint. They are logic level gates from my testing and drawing out their configuration from the original PCB that I pulled with the engine. In my testing with a 1k resistor from the CPU to the Gate with a 100k resistor to ground and the Source connected to ground it only pulls 50uA

Cool! Except the bit where you don't know what they are :-) Probably best to choose something else that is suitable instead, which leads to...

I found FQD12N20LTM 9Amp QFETs or VND5N07 5Amp OmniFETs that have the same DPAK footprint so they can be switched easily.

I believe VND5N07 is obsolete, and are you sure they are dpak and not d2pak? Consider the smaller one to save space :-) The other part you listed has an RDS on of 280milli Ohms at 10v gate voltage... it will generate quite a bit of heat. Plus it's unprotected. It is cheap, though. VNB14NV04 is a nice part in a dpak. Recommended by me :-) Up to you, though. If the footprints match, list whatever and decide later.

For the Fuel Pump relay out, I found a VNN1NV0413TR OmniFET rated at 1.7A in a SOT-223 footprint.

That's fine, beware of RDS on if you try to load it more heavily, though.

You and Dan have given me a lot of great information that I will incorporate in my design :-)

That's what it's all about :-)

I have also attached a pic of the car Jaguar is being designed for...

Too cool :-)

All of the cars/engines to run so far have something a bit special about them, but this one is probably the coolest :-)

Fred.

[Fred]

It's been pointed out to me that my advice re low uF values on the power supplies is not good. 47uF tants is a great choice. You can go lower depending upon which reg you use and how much you intend to take from it.

[DeuceEFI]

VNB14NV04 is a nice part in a dpak. Recommended by me

VNB14NV04 is a D2PAK package which is bigger than the VND14NV04 which is the same series in a DPAK package. I have revised my schematic and board layout to use the VND14NV04 for the Injectors and for the Fuel Pump relay FETs. Thanks for the suggestion!

I have updated all the schematics and redesigned the board based on those suggestions. I have updated the files on https://github.com/DeuceEFI/Jaguar

Let me know your thoughts...

Andy

[Fred]

My apologies on the B/D thing. You're on the right track :-)

Will review the schematic next time it's not cold enough to freeze the balls off of a brass monkey.

[Fred]

Nope, your schem PDF claims to be on it's side and corrupt/broken. Perhaps regenerate it? The previous one was OK. Checked on both mac and linux.

[DeuceEFI]

Sorry about that, I'll get a new PDF generated shortly.

Thanks for letting me know

[DeuceEFI]

Jaguar-Schematic.pdf has been updated on github.com.

I have also ordered some free samples from st.com from their OMNIFET-II and OMNIFET-III lines for prototype testing.

My samples orders from te.com (Tyco Electronics) have started to come in, just waiting on the connectors for the case/board... So far I only have the wiring harness connector and the female pins to crimp the wires to.

The case that I'm going to use is made by Context Engineering Co. ( http://contextengineering.com ), Part # 3008H-5B which fits the 3" x 5" circuit board at 8 different levels plus they also have a Part # 4006-6B which fits a 4"x 6" circuit board at 6 different levels. Both give me the ability for an additional add on card if necessary in the future.

Thanks it for this update

[DeuceEFI]

Crankshaft and Camshaft Position Sensor information:

Both are Hall Effect Sensors, the signals are digital HI/LO and I have attached the graph of the output signals over a complete firing order cycle.

Andy

I will be feeding both of these inputs (crankshaft and camshaft) sensors thru a MAX9926UAEE+ chip that I just happened to have ordered a free sample from Maxim IC this past July, so no worries about testing...

Also I am in the process of updating the BOM file called Jaguar.ods which will also track the remaining components that I need to purchase once we have finalized my design so I can start the prototype process.