SLC DIY Wideband Controller with EGT and more!

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Fred
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Re: SLC DIY Wideband Controller with EGT and more!

Post by Fred »

Thanks for the excellent explanation, Alan.

I have a couple of questions given that you're in here anyway :-)

1) What IS that device I soldered in for, if not some sort of temp measurement?
2) Can you summarise the differences between SLC DIY, SLC Pure Plus and SLC OEM?
3) Are there any pics of the guts of the Pure Plus to see?

I have some feedback for you too, but wanted to hook it up and try it first.

I actually built it without the manual because I understood that it was a prototype from our conversation. I got it all right, luckily, but many of the questions I wrote down were answered easily by the contents of your document.

One piece of feedback up front, supply the user manual as a seperate download, it's annoying to have to install the software to read the book. Also, along the same lines, can the software be run using Mono on Linux? And/or is the interface specification available (As it IS with Innovate) such that we could write an app to talk to it that would run on linux, assuming yours wont (I saw something about VB in there).

Thanks again :-)

Fred.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by toalan »

Hi Fred.

The manual is available as a separate download, it has been available as a separate download for about 2 months. Originally the manual and software was packaged together.

1)which device? Maybe you are talking about the black bulb thing near the usb and molex connector? If so that is a thermistor used for cold junction compensation for the EGT.
2)

SLC DIY: $99 USD
-DIY kit
-AFR display, EGT display(with egt probe), Boost display (with boost sensor)
-seven 0-5[v] analog input channels
-USB
-RPM pickup
-Single fuse, protects electronics
-The rest is the just standard stuff; linear output, NB output, 0.01 lambda accuracy, etc...

SLC Pure Plus: $160
-Fully assembled, plug and play
-AFR display
-Free Air Calibration feature, can be used without free air calibration
-single 0-5[v] datalogging channel
-RPM pickup
-Dual fused, protects electronics and sensor
-USB
-The rest is the just standard stuff; linear output, NB output, 0.01 lambda accuracy, etc...

SLC OEM:
- It is a different animal than the other 2. SLC OEM is meant to be integrated into other people's electronic designs, such as FREEEMS.
-Need just 5v supply to operate, needs an addition 50 cent TVS array for automotive use.
-0.01 lambda accuracy
-Free Air Calibration feature, can be used without free air calibration
-0-5[v] linear output
-I2C interface if you want to use it.

If you have decent soldering capability then I would reccommend SLC DIY, it is packed with features and is very well priced. If you are after plug and play with basic datalogging then SLC Pure Plus is a good choice.

the PC software is built in visual basic 6, I am a very bad a programming anything that has more than 32k flash and 4k ram, so I have no plans on doing anything with linux. I do have a documentation on the serial protocol, which needs to be updated, somewhere on my forum.

3) guts, sorry nothing available yet. The schematic for SLC Pure Plus is almost identical to SLC DIY(which is available), infact I can run the SLC DIY firmware on SLC Pure Plus. The big difference IMO, is that the analog datalogging channels to the mux on SLC DIY are not current or voltage protected, that is a weak point in my design but there is no room to ram in protection on all 7 channels, the mux is in a socket so it can be replaced if damaged. SLC Pure Plus has only a single datalogging channel, so it was no sweat to protect it.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by EssEss »

great explanations - right for the throat - just what I needed to hear.
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Fred
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Re: SLC DIY Wideband Controller with EGT and more!

Post by Fred »

I thought about telling you that you were picking on the wrong guy ;-) Alan is a good bloke :-)

Thanks for the answers, this is good summary info for anyone looking over the thread!

Fred.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by EssEss »

nah - not picking on anyone. I have my doubts about any company that writes up stuff to sound technical without providing the tech. Having a technical background makes writeups like that glow like they're neon.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by MotoFab »

It sounded like Sean knows you and was just goofing around. Sorry Alan, if it looked like a dogpile.

Very elegant design. And that's a well-divided set of products using the same foundation.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by toalan »

All is well that ends well. On the flip side I would be the first to be cynical of any technical sounding jargon and claims myself.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by jharvey »

I see your power supply is very similar to the one we have drafted for FreeEMS 1.0. You used the adjustable reg with caps on the lower part of the divider vs the 5v reg we have. I'm curious if you have any feed back or recommendations for the power supply we have drafted up.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by toalan »

Is this the circuit? http://i324.photobucket.com/albums/k352 ... S_pg30.gif

It looks good to me, you got the reverse diode, over voltage, and the diode to stop the regulator from being back powered. I do not see a fuse though, but that can be added externally. What is the regulator you are using?

I am very partial to using the lm317t, because it has been around for a long time, has multiple sources so it is priced competitively. It is not load dump and reverse voltage rated, but I would rather take care of that myself. The feedback on the LM317t is a really nice feature for me, the heater on the lambda sensor gets switched with upto 3 amps at ~1khz, the feedback does a good job at ripple rejection. On an ECU you will have to deal with injector switching, so something with feedback like the lm317 might be of interest to you. Generally with 1% feedback resistors the 5v output is closer to 5v than most low cost 5% non feedback type regulators.

I am going to experiment with some like this in my next design, http://www.avrfreaks.net/index.php?name ... ic&t=92396, looks like a really solid and elegant way for voltage protection.
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Re: SLC DIY Wideband Controller with EGT and more!

Post by MotoFab »

Hey there Alan. When you're talking about regulator feedback, are you referring to R11 and R12 in this schematic: SLC_DIY_Jan_5_2010_Schematic.pdf? If so, all fixed voltage linear regulators have that feedback circuit. It's just internal.

Something to be aware of, the capacitors C3 and C8 will slow the response to output voltage changes. Putting caps between the voltage divider creates a low pass filter on the feedback input, and slows the transient response. Those caps will not prevent oscillation or regulator transients, and they will cause transients at particular frequencies.

The output capacitance is what prevents oscillation. Though many new linear regulators don't require caps on the input, and only a single high freq cap of 0.1uF on the output. Their response is so accurate to low frequency transients, like inductive load switching, that a large output capacitance is unnecessary.
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