Gaf,
I have a few IGBT around here that should work fine, I used them in some DC chopper drives a while back and have some left over.
In my truck I have a HEI distribitor and it has a modual that outputs a signal each time a piston reaches TDC and then recieves a dwell PWM signal to fire the Coil how so they figure the dwell do they take in the pulse then just average out the timming advance dwell compared to the RPM of the motor or is their other variables happening?
I would like to convert my truck over to coil per plug like the newer motors run and keep up with the timming with a better RPM sensor say maybe like a resolver with as many teeth as cylinders plus one extra Sync notch.
Ibsen,
Unless you are using sequencial fuel injection where each cylinder is firing the it own injector at a certain time it does not matter how many cylinders the motor has it because most EFI systems fire in a Batch of all the injectors or bank to bank where they fire from left bank to right bank. So you can take the same controller to run a 2 cylinder or a 12 cylinder it only needs the right injectors and VE table (tune) setup.
You are right, I was thinking about Ignition control...
If we used Waisted Spark Ignition control we only need half the number of I/O's to # of cylinders ( I think I got that right)...
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
*.*
Ibsen
" It's nice to be important, but ·· more important to be nice... "
Ibsen,
I see you are talking about the mutispark control of an MSD ignition, I dont think to many OEMs use it. I dont think I need it in my truck I have ran the MSD boxes and the HP gained is not to much a little better fuel economy but very little.
bennettdan,
Those IGBT's should work fine to drive to ignition coil.
For you truck motor, not sure of the model and year but it still may have a centrifugal advance located below the breaker plate.·This would handle the spark advance with RPM but not with throttle position.· In the past that was handeled with a venturi vacuum applied to·a diaphram·attached to the breaker plate.
For injection timing, all manufactures today use sequencial injection timing.··Even though this is common, when to inject the fuel varies alot.· At·Ford we calculated when the end of injection would occur the started the injection·so that it would finish before the intake valve opened.· This provided the longest resident time·for most of·the fuel to vaporize.· At WOT and higher engine speeds this is not possible since injectors are just about full on (90%).· That is if the injector is sized properly for the engine.· Small enough so that idle pulse width is gearter 1ms and peak·pulse width approaches approx 90% injector on time.
John,
All you need to do for the extra Injectors is use an Optoisolator connected to the SX pin you have the Injector mosfet on and then out of the Optoisolator to 4,6 or 8 mosfets for a batch injection or use two Optoisolators one on each of two SX pins so you can have bank to bank injection or use an an OptoIsolator for each Injector mosfet per cylinder not many people will need more than 8 cylinders but others could be added and then we can create a daughter card if the need be. But we need the optos to protect the SX from spikes and the mosfets need reverse diodes also.
GAF,
The new cars that have sequencial use it to make better fuel economy not so much for HP right? I have been seeing alot of high HP motors latly that use say 16 injectors on an 8 cylinder so that it will provide the Idle quality with the smaller ones running sequencial and when the boost kicks in they run both sets at bank to bank then batch for full out racing.
Guys,
Remember their are so many options when making your own system so why dont we settle on a PCB layout that has the ability to run all options that we can think of then only code in what you need for your application and we might get a group buy on the PCB boards.
On my truck I want to be able to add a turbo some day so I would like to be able to run extra injectors so we need a connector to run a addon daughter board, also sense a wideband O2 may be used it needs a A/D converter instead of just a comparator circuit. I would also like for it to control a TCU transmission controller for different makes of auto so another connector is needed for it.
So how about we make suggestions and I add it to this Post and then when we all agree we see how much we can have them made for? ················································································· Type of signal:
We have 40 pins to play with here.···············································
1)·Injectors for batch firing 40-1=39···pins left································ PWM Out
2) MAP (manifold absolute sensor) 39-1=38····································· Analog In
3) O2 sensor 38-1= 37································································ Analog In
4) IAT (Idle air temp sensor) 37-1=36············································ Analog In
5) Fuel Pump Relay out 36-1=35···················································· Digital Out
6) RPM input 35-1=34··································································Pulse In
7) IAC ( Idle air control motor/valve) 34-1=33································· Digital Out
8) CTS ( coolant temp sensor) 33-1=32········································· Analog In
9) Ignition outputs from single coil to muti coil 8 outputs 32-8=24······· Digital Out
10)TPS (throttle position sensor) 24-1=23······································ Analog In
11) TCU for a chevy·4L60E tranny it takes 11-14 pins.··23-14=9·········PWM,Digital IN/Out,Analog
12) Second MAP sensor for altitude correction. 9-1=8 pins left··········· Analog In·····
13) Knock sensor. 8-1= 7···························································· Digital In
14) MAF ( Mass air flow) sensor 7-1=6··········································· Analog In
15) Oil Pressure Switch 6-1= 5····················································· Analog In
16)
Anyone else got anything to add?
Post Edited (bennettdan) : 6/2/2007 7:15:07 AM GMT
Ibsen,
You could have the sensor correct for that each time the vehicle starts up. The Map should read what the pressure is outside just before startup.
Or do you want it correct as you are drive? I dont know if you would need it unless you traveled alot of long trips.
Team, ··· As far as the Pins needed they could be less if you use a multi channel A/D converter.
Post Edited (bennettdan) : 6/2/2007 7:16:09 AM GMT
IGBTs or Mosfets are better to drive the injectors?
bennetdan,
Why do we need PWM Output for the injectors?
Wouldn't a simple high or low output will do?
What is this TCU thing about? Seems like wasting a lot of pins.
16.) Serial Port to PC or Notebook ( 2 pins)
17.) Serial Port to Propeller chip to display RPM and such on a small LCD TV. (2 pins)
John,
The Murata 20Mhz and 50Mhz thru hole ceramic resonator that Parallax sells will do just fine.
Don't forget a 1M ohm parallel resistor across OSC1 and OSC2 for stability.
William,
Most all of the Fuel injection controllers vary the duty cycle to the injectors so PWM should be the best. The TCU is a Transmission controller for electronic trannys.
Just a quick note. As noted above, it might be useful to incorporate an SX48 into the design. The SX48 proto board ($10) is just about 80mm x 100mm, so it might be handy for our next design to be a daughter board of the SX48 protoboard. That eliminates the need to solder the tiny leads of the SX48 and it provides a power source along with a programming port. Sounds like a nice neat stack to me!
SX48 board can supply up to 1 amp at 5VDC.
(FYI, 80 x 100mm is one of our board size limitations because that it the max that the free version of Eagle CAD will allow)
I have been·concerned·with the resources that are used by the·COUNT command for gathering RPM data. On my simplest system I eliminated RPM from the program all together and I·just use a very small map (6 TPS points) and correction by a CHT for an 80cc 2 stroke single. I have a·brake style dyno for small engines up to 30 HP, but I haven't needed to use it.
Do the Automotive manufactures calculate rpm by measuring the angular acceleration, between two points?, on a CPS or gear tooth sensor
Most manfactures use a 60 tooth spur gear in conjunction with a mag pickup attached to the dyno.· The·the output of the mag pickup is converted into a square wave and they just count the pulses for a fixed period of time.
On the engine there is a 40 tooth gear·keyed to the crank·and a single pulse generated at the camshaft.· The combination of these two signals provide·all the information that is necessay to calculate engine speed, injection timing, and ignition timing.
Is there such thing as a partially opened injector?
Can an injector be opened only partially or it must be opened fully at any time.
If there is no partial opening of injectors, then we don't need PWM for injectors.
Just a simple on or off will do.
I have·mostly used CHT's with the 14mm ring to fit under a spark plug or glow plug adapter. I would rather use a thermocouple that is screwed into the head, but often, castings are thin or it just isn't easy to do.·Has anybody seen a 14mm CHT that doesn't break easily or is it a problem best solved with braided thermocople wires instead of solid?
Also EGT's usally need to be within 3.5 to 7" from the piston or a valve. Is there a critical length for an O2 sensor?
Bill
also GAF, As an Engineer, have you authored or co-authored any SAE papers?,·Do you still work at Ford?
Post Edited (Capt. Quirk) : 6/4/2007 4:57:23 AM GMT
There is no such thing as a partially open injector, they are either on or off.
Capt. Quirk
I made a mistake on the number of teeth on the crank pickup.· The wheel that is keyed to the crank has 36 minus 1 teeth.· The reason for the minus 1, is there is a missing tooth, that allow the processor to determine crank position.· In·addition the cam sensor would allow it figure out cycle position.
Yes, I have been involved in a number of SAE papers, and also was on a SAE committe to rewrite SAE J1349 (engine prerformance rating).· I retired from Ford about a year ago.
Is there a significant·advantage to a sequental EFI system, where all cylinders are monitored and controled as individual cylinders to maintain a power balance between all cylinders ?
Works nice on a 2 stroke twin, but I would only call it an advantage over similar race engines.
After all these years, do you prefer a "good" Carb or·"good" EFI?
Post Edited (Capt. Quirk) : 6/5/2007 6:06:59 AM GMT
1. Are the Injectors usually common ground, common positive or floating?
2. Can we open 2 or more injectors together at the same time using one MOSFET?
3. In your opinion, IGBT or MOSFETs are more suitable for driving injectors?
1. The injectors are held at 12VDC then pulled to ground, through the driver, to turn them on.
2. You should use a single driver for each injector
3. You could use either an IGBT or a MOSFET as a injector driver, just make certain it has a high enough rating to handle the load.· Aleast a couple hundred volts with a internal diode for the fly-back voltage and about 10 amp rating.
Capt. Quirk
Manfactures use sequential injection for the best cylinder to cylinder balance and to keep feedgas emissions to a minimum (better fuel prep and good cylinder-to-cylinder distribution).
After all these years of working on·engines I do prefer Fuel Injection, because it works so damn good.··I think you would need·to work·on a A/F distribution problem·with a carb system for about 6 months to appreciate how good an EFI system really is. ··
GAF,
What do you know about timming circuits, do they use the 36 tooth and geartooth sensor to calculate the timming or do they use the cam sensor?
Also what is the usual frequency they pulse the Injectors? I have read its around 17khz.
Your idea of using the SX48 protoboard is fantastic.
Looks like we can use the IRL510 mosfets to drive the injectors since the injectors are common positive.
Don't forget the free-wheeling diodes.
Do you want 6 mosfets to cater for V6 engines or 4 mosfets to cater only for 4 cylinders?
I would think we start with 4 cylinders first, I wouldn't want to get too ambitious with a Version 1.0 board.
They use BOTH the 36 tooth gear and the pulse from the cam to determine where they are in the engine cycle.·
Injector Pluse:
Not sure what you are refering to, but they do NOT send out a frequency signal to open the injector.· As I explained in my last reply, one side of the injector is held at Vbat·and then·the other·side is brought to ground, through the driver, to open the injector.· This is a single pulse, not a frequency.
Comments
I have a few IGBT around here that should work fine, I used them in some DC chopper drives a while back and have some left over.
In my truck I have a HEI distribitor and it has a modual that outputs a signal each time a piston reaches TDC and then recieves a dwell PWM signal to fire the Coil how so they figure the dwell do they take in the pulse then just average out the timming advance dwell compared to the RPM of the motor or is their other variables happening?
I would like to convert my truck over to coil per plug like the newer motors run and keep up with the timming with a better RPM sensor say maybe like a resolver with as many teeth as cylinders plus one extra Sync notch.
Unless you are using sequencial fuel injection where each cylinder is firing the it own injector at a certain time it does not matter how many cylinders the motor has it because most EFI systems fire in a Batch of all the injectors or bank to bank where they fire from left bank to right bank. So you can take the same controller to run a 2 cylinder or a 12 cylinder it only needs the right injectors and VE table (tune) setup.
You are right, I was thinking about Ignition control...
If we used Waisted Spark Ignition control we only need half the number of I/O's to # of cylinders ( I think I got that right)...
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
*.*
Ibsen
" It's nice to be important, but
·· more important to be nice... "
I see you are talking about the mutispark control of an MSD ignition, I dont think to many OEMs use it. I dont think I need it in my truck I have ran the MSD boxes and the HP gained is not to much a little better fuel economy but very little.
William, I use three pin resonators where the center pin is ground. Is that the type of resonators you mean (i.e. "Ceramic Resonator CERALOCK")?
See page 11 of this datasheet:
http://eweb.chemeng.ed.ac.uk/jack/radio/projects/p16e9.pdf
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
John J. Couture
San Diego Miramar College
Those IGBT's should work fine to drive to ignition coil.
For you truck motor, not sure of the model and year but it still may have a centrifugal advance located below the breaker plate.·This would handle the spark advance with RPM but not with throttle position.· In the past that was handeled with a venturi vacuum applied to·a diaphram·attached to the breaker plate.
For injection timing, all manufactures today use sequencial injection timing.··Even though this is common, when to inject the fuel varies alot.· At·Ford we calculated when the end of injection would occur the started the injection·so that it would finish before the intake valve opened.· This provided the longest resident time·for most of·the fuel to vaporize.· At WOT and higher engine speeds this is not possible since injectors are just about full on (90%).· That is if the injector is sized properly for the engine.· Small enough so that idle pulse width is gearter 1ms and peak·pulse width approaches approx 90% injector on time.
·
All you need to do for the extra Injectors is use an Optoisolator connected to the SX pin you have the Injector mosfet on and then out of the Optoisolator to 4,6 or 8 mosfets for a batch injection or use two Optoisolators one on each of two SX pins so you can have bank to bank injection or use an an OptoIsolator for each Injector mosfet per cylinder not many people will need more than 8 cylinders but others could be added and then we can create a daughter card if the need be. But we need the optos to protect the SX from spikes and the mosfets need reverse diodes also.
GAF,
The new cars that have sequencial use it to make better fuel economy not so much for HP right? I have been seeing alot of high HP motors latly that use say 16 injectors on an 8 cylinder so that it will provide the Idle quality with the smaller ones running sequencial and when the boost kicks in they run both sets at bank to bank then batch for full out racing.
Guys,
Remember their are so many options when making your own system so why dont we settle on a PCB layout that has the ability to run all options that we can think of then only code in what you need for your application and we might get a group buy on the PCB boards.
On my truck I want to be able to add a turbo some day so I would like to be able to run extra injectors so we need a connector to run a addon daughter board, also sense a wideband O2 may be used it needs a A/D converter instead of just a comparator circuit. I would also like for it to control a TCU transmission controller for different makes of auto so another connector is needed for it.
So how about we make suggestions and I add it to this Post and then when we all agree we see how much we can have them made for?
················································································· Type of signal:
We have 40 pins to play with here.···············································
1)·Injectors for batch firing 40-1=39···pins left································ PWM Out
2) MAP (manifold absolute sensor) 39-1=38····································· Analog In
3) O2 sensor 38-1= 37································································ Analog In
4) IAT (Idle air temp sensor) 37-1=36············································ Analog In
5) Fuel Pump Relay out 36-1=35···················································· Digital Out
6) RPM input 35-1=34··································································Pulse In
7) IAC ( Idle air control motor/valve) 34-1=33································· Digital Out
8) CTS ( coolant temp sensor) 33-1=32········································· Analog In
9) Ignition outputs from single coil to muti coil 8 outputs 32-8=24······· Digital Out
10)TPS (throttle position sensor) 24-1=23······································ Analog In
11) TCU for a chevy·4L60E tranny it takes 11-14 pins.··23-14=9·········PWM,Digital IN/Out,Analog
12) Second MAP sensor for altitude correction. 9-1=8 pins left··········· Analog In·····
13) Knock sensor. 8-1= 7···························································· Digital In
14) MAF ( Mass air flow) sensor 7-1=6··········································· Analog In
15) Oil Pressure Switch 6-1= 5····················································· Analog In
16)
Anyone else got anything to add?
Post Edited (bennettdan) : 6/2/2007 7:15:07 AM GMT
That will allow the system to compensate for altitude.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
*.*
Ibsen
" It's nice to be important, but
·· more important to be nice... "
Post Edited (Ibsen) : 6/2/2007 3:39:01 AM GMT
I like the MSD due to the distributor less setup !!!
I'm all about less mechanical and moving parts...
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
*.*
Ibsen
" It's nice to be important, but
·· more important to be nice... "
You could have the sensor correct for that each time the vehicle starts up. The Map should read what the pressure is outside just before startup.
Or do you want it correct as you are drive? I dont know if you would need it unless you traveled alot of long trips.
Team,
··· As far as the Pins needed they could be less if you use a multi channel A/D converter.
Post Edited (bennettdan) : 6/2/2007 7:16:09 AM GMT
You need to use a serial multichannel A/D converter, the SX48 does not have an internal A/D converter...
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
*.*
Ibsen
" It's nice to be important, but
·· more important to be nice... "
IGBTs or Mosfets are better to drive the injectors?
bennetdan,
Why do we need PWM Output for the injectors?
Wouldn't a simple high or low output will do?
What is this TCU thing about? Seems like wasting a lot of pins.
16.) Serial Port to PC or Notebook ( 2 pins)
17.) Serial Port to Propeller chip to display RPM and such on a small LCD TV. (2 pins)
John,
The Murata 20Mhz and 50Mhz thru hole ceramic resonator that Parallax sells will do just fine.
Don't forget a 1M ohm parallel resistor across OSC1 and OSC2 for stability.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my
www.mercedes.com.my
Most all of the Fuel injection controllers vary the duty cycle to the injectors so PWM should be the best. The TCU is a Transmission controller for electronic trannys.
Just a quick note. As noted above, it might be useful to incorporate an SX48 into the design. The SX48 proto board ($10) is just about 80mm x 100mm, so it might be handy for our next design to be a daughter board of the SX48 protoboard. That eliminates the need to solder the tiny leads of the SX48 and it provides a power source along with a programming port. Sounds like a nice neat stack to me!
SX48 board can supply up to 1 amp at 5VDC.
(FYI, 80 x 100mm is one of our board size limitations because that it the max that the free version of Eagle CAD will allow)
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
John J. Couture
San Diego Miramar College
#18 CPS, Crankshaft position sensor
I can draw one up in expressPCB their boards can be alot bigger but it has to be made by them.
I have been·concerned·with the resources that are used by the·COUNT command for gathering RPM data. On my simplest system I eliminated RPM from the program all together and I·just use a very small map (6 TPS points) and correction by a CHT for an 80cc 2 stroke single. I have a·brake style dyno for small engines up to 30 HP, but I haven't needed to use it.
Do the Automotive manufactures calculate rpm by measuring the angular acceleration, between two points?, on a CPS or gear tooth sensor
Bill
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
*.*
Ibsen
" It's nice to be important, but
·· more important to be nice... "
That's a possibility. Let's see where this project leads us and use that as a backup plan.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
John J. Couture
San Diego Miramar College
Most manfactures use a 60 tooth spur gear in conjunction with a mag pickup attached to the dyno.· The·the output of the mag pickup is converted into a square wave and they just count the pulses for a fixed period of time.
On the engine there is a 40 tooth gear·keyed to the crank·and a single pulse generated at the camshaft.· The combination of these two signals provide·all the information that is necessay to calculate engine speed, injection timing, and ignition timing.
Is there such thing as a partially opened injector?
Can an injector be opened only partially or it must be opened fully at any time.
If there is no partial opening of injectors, then we don't need PWM for injectors.
Just a simple on or off will do.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my
www.mercedes.com.my
Also EGT's usally need to be within 3.5 to 7" from the piston or a valve. Is there a critical length for an O2 sensor?
Bill
also GAF, As an Engineer, have you authored or co-authored any SAE papers?,·Do you still work at Ford?
Post Edited (Capt. Quirk) : 6/4/2007 4:57:23 AM GMT
There is no such thing as a partially open injector, they are either on or off.
Capt. Quirk
I made a mistake on the number of teeth on the crank pickup.· The wheel that is keyed to the crank has 36 minus 1 teeth.· The reason for the minus 1, is there is a missing tooth, that allow the processor to determine crank position.· In·addition the cam sensor would allow it figure out cycle position.
Yes, I have been involved in a number of SAE papers, and also was on a SAE committe to rewrite SAE J1349 (engine prerformance rating).· I retired from Ford about a year ago.
Is there a significant·advantage to a sequental EFI system, where all cylinders are monitored and controled as individual cylinders to maintain a power balance between all cylinders ?
Works nice on a 2 stroke twin, but I would only call it an advantage over similar race engines.
After all these years, do you prefer a "good" Carb or·"good" EFI?
Post Edited (Capt. Quirk) : 6/5/2007 6:06:59 AM GMT
A few more questions if you don't mind.
1. Are the Injectors usually common ground, common positive or floating?
2. Can we open 2 or more injectors together at the same time using one MOSFET?
3. In your opinion, IGBT or MOSFETs are more suitable for driving injectors?
Thanks.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my
www.mercedes.com.my
Injectors:
1. The injectors are held at 12VDC then pulled to ground, through the driver, to turn them on.
2. You should use a single driver for each injector
3. You could use either an IGBT or a MOSFET as a injector driver, just make certain it has a high enough rating to handle the load.· Aleast a couple hundred volts with a internal diode for the fly-back voltage and about 10 amp rating.
Capt. Quirk
Manfactures use sequential injection for the best cylinder to cylinder balance and to keep feedgas emissions to a minimum (better fuel prep and good cylinder-to-cylinder distribution).
After all these years of working on·engines I do prefer Fuel Injection, because it works so damn good.··I think you would need·to work·on a A/F distribution problem·with a carb system for about 6 months to appreciate how good an EFI system really is.
··
What do you know about timming circuits, do they use the 36 tooth and geartooth sensor to calculate the timming or do they use the cam sensor?
Also what is the usual frequency they pulse the Injectors? I have read its around 17khz.
Your idea of using the SX48 protoboard is fantastic.
Looks like we can use the IRL510 mosfets to drive the injectors since the injectors are common positive.
Don't forget the free-wheeling diodes.
Do you want 6 mosfets to cater for V6 engines or 4 mosfets to cater only for 4 cylinders?
I would think we start with 4 cylinders first, I wouldn't want to get too ambitious with a Version 1.0 board.
How long did you take to learn eagle?
Thanks.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my
www.mercedes.com.my
Signal Timing:
They use BOTH the 36 tooth gear and the pulse from the cam to determine where they are in the engine cycle.·
Injector Pluse:
Not sure what you are refering to, but they do NOT send out a frequency signal to open the injector.· As I explained in my last reply, one side of the injector is held at Vbat·and then·the other·side is brought to ground, through the driver, to open the injector.· This is a single pulse, not a frequency.