Peak and hold injector driver board

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JAM
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Post by JAM »

I asy my injector driver boards a while back and i am now putting them into my MS2 case to wire them up. I am running 8 inj/2 boards and i need some info on how to wire the second board. I did not see a diagram on the website for 2 boards.

Also, What gauge wire do you use between the MS and P&H boards, and what gauge to the injectors? I would assume the use of strand wire for both.

As far as the method for connecting to injectors, it seems to be easiest just to run a separate a connector and not mess with the DB 37 connector. Is my assumption correct that if i use a separate connector i will not have to run the wires on the bottom side to the DB 37?

In the MS II asy (step 71), should i leave R37 and R38 out all together or put the jumper in?
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Post by racingmini_mtl »

JAM wrote:I asy my injector driver boards a while back and i am now putting them into my MS2 case to wire them up. I am running 8 inj/2 boards and i need some info on how to wire the second board. I did not see a diagram on the website for 2 boards.

Also, What gauge wire do you use between the MS and P&H boards, and what gauge to the injectors? I would assume the use of strand wire for both.

As far as the method for connecting to injectors, it seems to be easiest just to run a separate a connector and not mess with the DB 37 connector. Is my assumption correct that if i use a separate connector i will not have to run the wires on the bottom side to the DB 37?

In the MS II asy (step 71), should i leave R37 and R38 out all together or put the jumper in?
The easiest way to connect 2 boards is to have one board connected to injector channel 1 and the other board connected to injector channel 2. That means that instead of connecting 2 pads on the p&h board to pin 5 of U4 and 2 pads to pin 7, you connect all 4 pads to pin 5 on one p&h board and all 4 pads to pin 7 on the other board. You also connect the 5V pad and ground pad as indicated (6th and 5th pads respectively on the JP1 header).

The wires going from the MS board to the p&h board don't carry much current so using 28 gauge wire will be fine. If you have something bigger, it will be fine also but it will take more space which is an important factor with 2 p&h boards. You can use 18 or 20 gauge wires (as indicated in the Megamanual) for the injectors and the injector grounds. If you use fewer ground wires, you may want to go to 16 or 14 depending how many wires you use. Don't forget that the peak current is 4A per injector so if you have all 8 injectors firing simultaneously, you have 32A going to the ground. In that case, a couple of 14 gauge wires (or more) would be good to have. And, as you say, you want stranded wire in all cases.

For the injectors, as you say the best way would be to use a separate connector especially since you have 2 boards. With a separate connector you don't need to run wires on the bottom side because you're not using the DB37 at all. The advantage is also that all the high current from the injectors is removed from the MS board so this eliminates one potential noise source.

R37 and R38 can be left out completely because they are bypassed when using the p&h board.

Cheers,
Jean
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JAM
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Post by JAM »

Thanks for the info.

So if i understand correctly, i should run the banded side of D17 to one board, and the banded side of D18 to the other. If this is the case, i will need to split the one wire 4 ways. what is the best way to do this and is the 28gauge still sufficient as indicated in your last reply?

On another note, on the diagrams you have on your site, It seems that the boards have 4inputs and a 5Volt reference on the bottom. I have the board with 6, the left one is square. What is that for?
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Post by racingmini_mtl »

JAM wrote:So if i understand correctly, i should run the banded side of D17 to one board, and the banded side of D18 to the other.
That's correct.
JAM wrote:If this is the case, i will need to split the one wire 4 ways. what is the best way to do this and is the 28gauge still sufficient as indicated in your last reply?
The 28 gauge wire will still be fine. What you can do is connect the wire to the first input and use jumpers to connect the other inputs. The jumpers can be made with the extra length of leads you clip off from the resistors (or other components). Don't use the clip-offs from the sense resistors or the diode because they will be too big.
JAM wrote:On another note, on the diagrams you have on your site, It seems that the boards have 4inputs and a 5Volt reference on the bottom. I have the board with 6, the left one is square. What is that for?
The diagram shows the v1.0 board. On the v1.1 board you have, there is an additional ground. The first 4 holes are the 4 inputs on both boards, the last hole is the 5V input (6th hole on your board) and the 5th hole on the v1.1 board is the ground connection for the LM1949. This needs to be connected to a ground on the MS board. You could use the negative side of C14 for that.

Let me know if you need more information.

Cheers,
Jean
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JAM
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Post by JAM »

Thanks for bringing me up to speed. If i can jumper the inputs with a resistor lead, there must not be much current to the input. You mentioned to run the 28 ga wire to the 1st input, but if they are jumpered i would assume any of the 4 inputs would work, right? and just for the record the 28ga also is used for the 5v?

Another question of curiosity, if the v1.1 board has an extra ground, how did you ground v1.0?



Thanks again Jean
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Post by racingmini_mtl »

As long as all the 4 inputs are connected together you can have one wire connected to any of the 4 inputs and it will work fine. And the 5V and ground (on the fifth hole at the bottom of the board) connections can also be connected by 28 gauge wire. The 4 injector ground connections (at the top of the board), as well as the 4 injector connections (also at the top of the board), need to have the previously mentioned 18 gauge wires.

So you should have 11 wires coming out of one p&h board: 3 28-gauge wires connected to the MS board and 8 18-gauge wires going outside the MS case connected to the 4 injectors and to the chassis ground. The 4 injector ground wires can be connected together anywhere between the p&h board and the chassis ground but if you connect them before the chassis ground, you'd want to have a 14-gauge wire from the connection point to the chassis ground.

The v1.0 had the LM1949 grounds connected to the injector grounds. This was fine but to prevent the possibility of noise being introduced from the high-current side to the low-current side through the ground, the ground plane was separated in 2: injector grounds (high-current) and LM1949 ground (low-current). This required the addition of the new ground connection (low-current).

Cheers,
Jean
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JAM
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Post by JAM »

OK, i think i am getting the hang of this. One more thing, If i use use the negative side of C14 to ground one board, how would you suggest grounding the other board?
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Post by racingmini_mtl »

You could run 2 wires from that place or you could use the negative side of D21 (non-banded side).

What are you doing for 5V? Running 2 wires from the positive side of C14? You could also use the positive side of D21.
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JAM
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Post by JAM »

I like the idea of running 2 different wires to the the ground as well as the 5V. I looked all over town for 28ga stranded wire and all i can find is 22 ga. That may have to do for now, but i have a plan for a creative way for the output to exit the case............ i will keep you posted and send pictures if it turns out as planned
racingmini_mtl
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Post by racingmini_mtl »

You should be fine with the 22-gauge wire. It'll just be bit bulky. I look forward to see how it turns out. :)

Cheers,
Jean
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JAM
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Post by JAM »

I mounted my boards into the top of the case today. Everything went good besides one of the screws in the transistor interfered with the 6 jumper pin cluster sticking up in the MSII daughter card. It is about a .050 interference, so i just cliped about 1/16" off the jumper pins and everything fits. Not sure what those 6 are used for as i have only used the 1 jumper set to load the firmware. If i have to use them it still seems that the supplied jumper will work judging by the nature of the jumper. I hope i did not screw up my board......... :?

A question about the mounting kit for the transistors. It lists 4 per board, but shouldnt it be 5/board? I do have some left over from my MS2 kit that i was going to use for the center transistor. Should i put heat sink compund on both sides of the mica insulator?

Also, does the top of the case seem to have enough cooling capacity for all of the transistors to keep cool or could it benefit from some extra heat transfer?
racingmini_mtl
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Post by racingmini_mtl »

It's very unlikely that you'll need to use the 6-pin header on the MS2. This is used to program the bootloader when the board is made and unless you plan to change it and you have a BDM cable, you're not going to use it.

The mounting kits in the BOM are for insulating the 4 TIP122s, It's true that there is also a need to mount the TIP42 but it doesn't need the insulating kit (which is a bit expensive) but could be mounted using any screw and bolt so it was not included in the BOM.

You should put heat sink compound on both sides of the mica. And I haven't personally run an engine with 2 boards but haven't heard of any problems from those who have. In any case, you should check if the case becomes hot as this will depend on where the case is installed and the specifics of your setup.

Jean
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cashsaudio
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Post by cashsaudio »

i dunno if i missed something but right now i have the engine on a stand just to test it outta the car and i currently have high imp. injectors can i still use this board to run them? Thanks

Jeff
2005 Honda S2000 getting MSnS Extra 3.0v with very many goodys. turboed
Jon k
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Post by Jon k »

cashsaudio wrote:i dunno if i missed something but right now i have the engine on a stand just to test it outta the car and i currently have high imp. injectors can i still use this board to run them? Thanks

Jeff
You don't need this board to run high impedance injectors
1992 BMW 525i M50 Non Vanos 24v Turbocharged
Stock COP Wasted Spark
MS2/E v3
racingmini_mtl
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Post by racingmini_mtl »

That's right that you don't need it for high impedance injectors but if you have the board installed because you plan on having low-Z injectors, you shouldn't have any problems running high-Z injectors with the board in the mean time.

Jean
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turbo355
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Post by turbo355 »

Im going to get some of these from you for some 2.2 boards im building.

But one question i have is will these also work with the Microsquirt to drive 4 low ohm inj. ?
racingmini_mtl
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Post by racingmini_mtl »

turbo355 wrote:Im going to get some of these from you for some 2.2 boards im building.

But one question i have is will these also work with the Microsquirt to drive 4 low ohm inj. ?
There are a couple of problems with using it with the Microsquirt.

The first is the form factor: the board is 4"x1.1" which means it fits perfectly in the top slot of the standard MS case which is 4" wide (as is the MS board). The Microsquirt is much smaller which means the p&h board will not fit inside the case.

You could fit the p&h board in another case outside the Microsquirt but that brings the second problem which is the type of signal needed for the board. The board is designed to be run from a 5V pulse for injector control which is what comes out of the Microsquirt CPU but not what comes out of the case. So you would either need to modify the Microsquirt to bypass the VND5N07 (uS injector drivers) to bring out the CPU signals or add a couple of transistors and a few resistors to modify the signal coming out of the uS. Modifying a surface mount board is not a very attractive proposition and it's not very easy to make a clean install with the second option.

I'm thinking of offering a small board to convert a standard injector signal that would allow the p&h board to be connected to any ECU in an outside box. I'm still not sure if I can make it in such a way as to make it attractive from a packaging and pricing point of view. I'm also not sure how much demand there is for it but if AEM can sell a similar box with 10 drivers, there must be some demand for it.

Jean
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turbo355
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Post by turbo355 »

Yeah i thought it might be a problem being the uS is surface mount. I was just checking out to make sure what i thought was correct. I need it to run 4 96lb injectors for piggy back and i didnt know how one would do it with the uS or even if it was possible.

I guess the standard board is still the best option.

Do you have the P&H and the VR boards in stock right now?

Also do you know if DIY auto tune caries your expansion boards i know they carry your stim (witch i just bought) ?
racingmini_mtl
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Post by racingmini_mtl »

I do have the boards in stock. Unfortunately, DIYAutotune only carries the JimStim. And I only have the bare boards because I don't have enough volume to be able to stock the components.

You can contact me directly at: boards at jbperf.com. This is also my Paypal address and you have the prices on my site.

Cheers,
Jean
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Jon k
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Post by Jon k »

Jean,

There definitely is demand for the external box. If I can avoid running an AEM product, I will.
1992 BMW 525i M50 Non Vanos 24v Turbocharged
Stock COP Wasted Spark
MS2/E v3
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