Is this possible?
jdefelic
Posts: 1
Hello,
I'm a toolmaker that knows a little about circuitry and but not much. My experience with the BS line is limited using a BS1 and some MOSFETs to control several solenoid valves and solenoids.
What i'm currently trying to accomplish is this: Controlling a 4 cylinder fuel injected engine with one of the BS2s. I know i can control the 4 injectors and have there open times increase depending on the RPM of the engine. But, now comes in the Throttle Position sensor. The TPS (throttle position sensor) is a potentiometer (i think), which Wikipedia tells me is a unit that "...provides a variable resistance dependent upon the position...". Is the BS2, or any of it's varieties, capable of sensing a change in voltage either increasing or decreasing and change the length of time the injectors are open even though the RPM have not increased yet? Like if the TPS moves rapidly in a increasing manner could the injector times change from 18ms to 25ms? Any help would be greatly appreciated. I'm do not know if what i want to do is even possible with a BS. I hope it is because it would be a really fun project.
Thanks, John
I'm a toolmaker that knows a little about circuitry and but not much. My experience with the BS line is limited using a BS1 and some MOSFETs to control several solenoid valves and solenoids.
What i'm currently trying to accomplish is this: Controlling a 4 cylinder fuel injected engine with one of the BS2s. I know i can control the 4 injectors and have there open times increase depending on the RPM of the engine. But, now comes in the Throttle Position sensor. The TPS (throttle position sensor) is a potentiometer (i think), which Wikipedia tells me is a unit that "...provides a variable resistance dependent upon the position...". Is the BS2, or any of it's varieties, capable of sensing a change in voltage either increasing or decreasing and change the length of time the injectors are open even though the RPM have not increased yet? Like if the TPS moves rapidly in a increasing manner could the injector times change from 18ms to 25ms? Any help would be greatly appreciated. I'm do not know if what i want to do is even possible with a BS. I hope it is because it would be a really fun project.
Thanks, John
Comments
As far as the principles involved, the Stamps can certainly measure a potentiometer (RCTIME) and send out variable length pulses.(PULSOUT)
The limiting factor with a fuel injection system is having the microprocessor (regardless of who the manufacturer is) fast enough to measure the throttle sensor, check the exhaust O2 sensor, calculate the injector pulse and then operate it. Obviously, high rpms need a pretty speedy micro.
Having said that, you might get a BS2sx to operate a throttle-body injector system on a medium speed 4 cylinder engine. Or move up to the SX series and probably have no trouble with a bit more sophisticated system.
Its all good fun....but don't take the family car apart until you've picked a week or so's groceries!
Regards,
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Tom Sisk
http://www.siskconsult.com
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http://forums.parallax.com/showthread.php?p=559030