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by **racingmini_mtl** » Wed Aug 22, 2007 1:21 pm

Scott,

You're right, the grounds are isolated so if you want to apply 5V to the ADC part it's not a problem. However, that changes the circuit especially with respect to the bias resistor. If you think that this makes sense then go for it.

Cheers,
Jean

by **MegaScott** » Thu Aug 23, 2007 10:56 am

racingmini_mtl wrote:Scott,

You're right, the grounds are isolated so if you want to apply 5V to the ADC part it's not a problem. However, that changes the circuit especially with respect to the bias resistor. If you think that this makes sense then go for it.

Cheers,
Jean

Not a problem, I'm not sure what i was thinking, all I need is the bias resistor to 5v, which can be easily done by lifting the one end and adding a short jumper wire. This way the Capacitors remain going to ground.

by **racingmini_mtl** » Fri Aug 24, 2007 7:08 pm

Here is a preliminary version of the BOM. The preliminary aspect is that it's just a quick enumeration of the Digikey part numbers. I'll have an Excel worksheet with all the details shortly.

For the dual VR part:

U1, U2: LM1815N-ND
R1, R6: 18KQBK-ND *
R2, R7: 330QBK-ND *
R3, R8: 1.0MEBK-ND
R4, R9: 4.7KEBK-ND
R5, R10: 50KEBK-ND
R11, R12: 1.0KEBK-ND *
C1, C5: 399-4232-ND
C2, C6: 399-4364-ND
C3, C7: BC1101CT-ND
C4, C8: BC1089CT-ND *
*as mentioned previously, these components may need to have their value adjusted and/or may need to be removed depending on the application. However, they should be a safe starting value.

For the ADC part (the values may need to be changed depending on the sensor used):

R13, R15, R17, R19: 1.0KEBK-ND
R14, R16, R18, R20: 1.0MEBK-ND
C9, C11, C13, C15: BC1089CT-ND
C10, C12, C14, C16: BC1103CT-ND

Cheers,
Jean

by **MoveX** » Mon Sep 03, 2007 1:31 pm

racingmini_mtl wrote:...
The schematic of the board is here (again click on the pic for a larger version):

...

Cheers,
Jean

One hint from me,
for missing tooth wheels it may be necessary to activate mode 2 (pin 5 to VCC) and to add an aditional resistor and 50-150kOhms between the peak detector pin 7 of the LM1815 and R3 and C2. Otherwise the peakdetector get's confused from the high voltage peak after the missing tooth/teeth which is stored into C2.

by **milesinfront** » Tue Oct 09, 2007 12:38 pm

Possibly a dumb question, but what is the intended use for JP2 & JP3?

Also, what are the ADC's used for?

by **racingmini_mtl** » Tue Oct 09, 2007 3:34 pm

JP2 and JP3 are for the different modes of the LM1815. You either leave pin 5 unconnected, connect it to ground, or connect to 5V to have all three modes. If you look at the LM1815 datasheet, you'll have the details of what the different modes are.

The ADCs are conditioners for when you want to use the 2 available ADCs from the CPU to log optional sensors. There are 4 circuits even though the CPU only have 2 unused ADCs because there was a request to have more for a different use. Since there was some space available, I added the 2 extra circuits which can just be left unpopulated if not needed.

Jean

by **turbo355** » Fri Dec 21, 2007 12:57 am

I have a question how do you figure what size cap.s or resistors to have a clean trigger up to say 12000 RPM ?

Forgot to say with a 24-1 crank trigger and a +1 cam signal

by **racingmini_mtl** » Fri Dec 21, 2007 1:15 am

At 12000 RPM and 24 teeth, you have a frequency of 4800Hz. If you look at the LM1815 datasheet, it says how to relate this frequency to the value of R and C. It even gives an example with 5Khz (which is about what you want) with a resistor value of 150K and a capacitor value of 0.001uF.

For more details look at the datasheet: http://www.national.com/ds/LM/LM1815.pdf

Jean

by **turbo355** » Fri Dec 21, 2007 1:57 am

Thank you very much. I learn something new everyday.LOL

by **turbodog** » Sun Dec 30, 2007 3:26 pm

racingmini_mtl wrote: It can also be used with MS2 (MS2 code, microsquirt code, MS2/extra code) and/or MS V3.0 for an additional VR input and the ADC inputs.

Jean

Hello, Jean. I find myself in need of an extra VR input, as I need to run "twin trigger" mode plus I want a cam sensor. Would your board enable this? How would I use the 3rd VR input for ignition sequencing?

Thanks in advance!

by **racingmini_mtl** » Sun Dec 30, 2007 4:48 pm

turbodog wrote:Hello, Jean. I find myself in need of an extra VR input, as I need to run "twin trigger" mode plus I want a cam sensor. Would your board enable this? How would I use the 3rd VR input for ignition sequencing?

Thanks in advance!

The board can only provide an interface between the VR sensor and the CPU. You would still need to have the firmware that could use the 3 inputs and I'm not aware of any version which allows that.

It would probably be possible to modify the MS2 code or the MS2/extra code to do that but it would not be trivial. You might want to ask for this feature on the MS2/extra development forum.

Jean

by **milesinfront** » Sun Jan 27, 2008 4:05 pm

I finally got this board installed yesterday! I'm only using it as a single VR conditioner for my V2.2 MS. Worked perfectly first try! Thanks for making these available...

by **aarc240** » Sat Feb 23, 2008 1:07 am

What's happened to the Excel BOM?

by **aarc240** » Sat Feb 23, 2008 1:07 am

What's happened to the Excel BOM?
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by **racingmini_mtl** » Sat Feb 23, 2008 9:00 am

If you look a few posts up you can find the part numbers but I've made an Excel BOM. You can find it here: http://jbperf.com/dual_VR/BOM_dual_VR_v1_0.xls

Jean

by **racingmini_mtl** » Sat Feb 23, 2008 9:00 am

If you look a few posts up you can find the part numbers but I've made an Excel BOM. You can find it here: http://jbperf.com/dual_VR/BOM_dual_VR_v1_0.xls Jean
P&H Board - Signal Interceptor Board (breakout board) - JimStim - Dual VR Board http://www.jbperf.com/
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by **mad max** » Wed Apr 09, 2008 9:48 am

some hint:
on a suzuki swift i have replace r2 by 4koms and ad 40k in vr1+ line

this way i have a 10/1 voltage divisor and i got input resistance closer to what i had measure on stock ecm

replace r1 by 10k (maybe smaller could be ok)

jumper c4

pin 5 not connected (mode1)

100k between pin7 and r3-c2

by **kritip** » Sun Apr 13, 2008 9:31 am

I have my PCB now

I'm looking at sourcing some LM1815N/NOPB in the UK.

Farnell sell them, but they are imported from US, so £16 delivery!!!!

They sell:

LM1815M/NOPB
LM1815N (without the /NOPB)

Digikey UK want £17 for S+H!!

I'm going to try and compare the specifications and see if i can use some uk stock. If anyone knows already though, can you let me know

Cheers,

Kristian

//EDIT ----------- M is the package type, so i def need N. However i can't see what NOPB stands for :S ... is it purely a lead free package?

by **racingmini_mtl** » Sun Apr 13, 2008 2:30 pm

kritip wrote://EDIT ----------- M is the package type, so i def need N. However i can't see what NOPB stands for :S ... is it purely a lead free package?

Yes you need N and yes NOPB is a lead free package. It's not mentioned for the N package because they're all lead free.

by **kritip** » Sun Apr 13, 2008 2:36 pm

Cheers Jean

I have 2 LM1815N on order now. £10 for the pair ($22USD) so not too bad. Can't wait for them to arrive to link it up now

Kristian

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