DIY reluctor anolog to digital converter

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Escort Paul
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DIY reluctor anolog to digital converter

Post by Escort Paul »

Hey peeps,
The ecu Im using haltech e11 wants a square wave (digital) signal can i do this by rectifying the signal of a reluctor.(as Im a cheap bast@rd and dont feel like spending $400 on the alternative ra-10 dual channel box )
Can anyone recommend diodes to use? or is there a cheap alternative.
Or should i half-rectify or full-wave rectify? although full wave will be a stronger (fatter) signal it might cause a double signal on the ecu as its still not quite digital.
Ive read on the web at high speed the voltage gets very high 100v not that I am totally convinced of that.

regards Paul
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jbelanger
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Re: DIY reluctor anolog to digital converter

Post by jbelanger »

Use an LM1815. It's specially designed for that.

By the way, I wasn't aware of the existence of the Haltech box but this is ridiculous. I have a DIY dual channel board (http://jbperf.com/dual_VR/index.html) and the kit is $30 (boards and components). You'd need a 5V power supply to truly compare with the Haltech but still gives you an idea of their margin.

Jean
Escort Paul
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Re: DIY reluctor anolog to digital converter

Post by Escort Paul »

thanks jbelanger I will be ordering 1 of your boards very soon.
now all i have to do is find a cheep 4 channel igniter and a WB controller and im set to go...
(yes Im looking at your 4 channel inj/igniter board.. is that suitable?)


a little info
Haltech are an Australian ECU producer with fairly high quality products, of which I picked up the last of e11v2 ecu at a bargin price.
I did say $400 for the dual channel which is wrong it's $200 but still very high for what it is.

I was going to be using another Aussie ECU producer called Adaptronic who have a very active forum and a DIY attitude, seem to have a good product.
I still may jump ship to them as Im finding haltech forum a little dead although the install manual is very well laid out .


regards Paul
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jbelanger
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Re: DIY reluctor anolog to digital converter

Post by jbelanger »

I knew about Haltech but not about their dual channel box. I also knew they're not cheap (but not to that point).

As for the 4 channel driver board, it depends on your application. If you have a logic level signal for each coil then you can use it as a 4-channel igniter. But you will need to mount it somewhere and provide a heat sink for the IGBTs. The board was dimensioned to fit in the standard Megasquirt case (and use the case as a heat sink) so that may not be suitable for you.

Also, this will be a dumb igniter module (i.e., the ECU has to take care of the dwell) and the only over current and temperature protection will be from the IGBT you chose. If you use a (cheaper) generic ignition IGBT, you will have to make sure you set the dwell and polarity correctly and monitor the coil and IGBT temperature initially to validate your configuration. Failure to do so may very likely result in fried coils and/or IGBTs.

Jean
Escort Paul
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Re: DIY reluctor anolog to digital converter

Post by Escort Paul »

the ra10 is only needed if the ecu doesn't get a clean enough signal apparently.
still curious if I could have got away with scotchy diode or not, altho I acknowledge your board does it properly.

just want to make sure I got this right

so bip373 for the IGBTs insulated to heatsink
The ECU (has 4channels for ignition) is setup to constant charge, set the dwell
and the ECU controls the coils by grounding the signal via your 4channel board.

hope that sounds right

regards Paul
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jbelanger
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Re: DIY reluctor anolog to digital converter

Post by jbelanger »

That sounds right. The ECU sends a 5V pulse (for the dwell duration) to the BIP373 (or another IGBT) which grounds the coil.

Jean
mk e
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Re: DIY reluctor anolog to digital converter

Post by mk e »

Escort Paul wrote:Hey peeps,
The ecu Im using haltech e11 wants a square wave (digital) signal can i do this by rectifying the signal of a reluctor.(as Im a cheap bast@rd and dont feel like spending $400 on the alternative ra-10 dual channel box )

regards Paul
Paul,
The haltech will be very happy with the signal from most relutor type pickups.....so the cheap bastard thing to do is just plug it in and go.

If you are using the haltech harness it will have a 4 lead (you will only need 2 of them) shielded cable with the shielding grounded at the ecu so all you need to do is connect the sensor. If you are making your own harness, the cable must be shielded with the shielding grounded at 1 end or the other, not both.

If you connect the sensor leads backwards (which is very easy to do on a few reluctor puickups I've seen) the engine will run but be very unhappy so it's a good idea to throw a scope in it to make sure before you fire up the engine.

Also, I see the need for a 5V power supply mentioned. The haltech has 5, 12 and I think 8V outputs that you coupld probably just use I would think??
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Fred
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Re: DIY reluctor anolog to digital converter

Post by Fred »

One trick for the VR wiring is to do the first version such that you can swap polarity easily to test each way and once sure that it's correct make it more permanent and tidy.

If you do swindle 5v from the Haltech for whatever purpose, do check that the current you require is less than the maximum that they rate the output for. The maximum rating could be quite low after all.

Fred.
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Escort Paul
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Re: DIY reluctor anolog to digital converter

Post by Escort Paul »

thanks mk e, I was well aware of that, your input is welcomed I was going to try to avoid signal issues altogether with a ra10 substitute, but had been reading the haltech forum and learned as you just said about try it first.
the dual channel board I will still get as I plan to use it as road speed/wheel slip indicator (as i have plenty lying around) for logging purposes and as far as i can tell it doesnt like vr signal for speed sensor acording to people on the forum.

a trick for VR sensors is to hook them up to a analog multimeter and sweep a spanner (something metal) toward the sensor and see if the meter moves positive or negative, when you pull the spanner away it should go opposite and that gives you your polarity. there will always be some timing movement with VR sensor's (even when wired correctly) but its not as bad as Haltech make it out to be

Fred, I havent come across how much current the 5volt can handle in their documentation or on the forum
and thanks for bringing that up its something I hadn't even thought about and its one of the more important issue's to be thinking about.
that definitely nixx's the idea of ecu(haltech can do it) control of my alternator way too risky plus added noise anyway.

Ive had a bit of a setback with this car.
I tried to register it in South Australia but the registration papers were incorrect which means full inspection before i can register
which also means new motor out, old motor back in, anti-pollution gear back on, cut new gearbox/engine mounts out, re-weld old mounts in.
You guys get the idea lots-o-cash and time, our inspection centre will not allow after-market ecu's in road vehicles.
selling the old motor was part of my budget for this car, it shouldnt stop me but has slowed down the project a lot.


all the fun of owning a project car :) regards Paul
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Fred
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Re: DIY reluctor anolog to digital converter

Post by Fred »

Gutted about the papers, good luck sorting that out!
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