Port WI build thread
#81
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HOWEVER, I'd love to see ZX do a test on his system, while it's still out of the car, where he drives the HSV at various duty cycles at its intended operating frequency, and makes two observations: First, does the volume of water actually emitted match the predicted flow based on the PWM table, and second, is the atomization quality consistent even at low flow rates?
So I had another thought on that. Joe maybe you can help. As mentioned previously I found a shareware PC app that creates a PWM square wave with variable frequency and DC. So, is there a quick circuit I can rig up with a transistor that would switch the transistor in response to what is essentially a PC audio out (headphone jack) signal? It would have to handle about 12W (P=V^2/R) at 100% DC on the load side. I would just have the transistor either switch to ground or switch to 12V DC, and vice versa the other end of the solenoid coil. I think 300 Hz would be the highest freq I would even think about trying, more like 200 Hz which is what I believe the valve is rated for. Too fast/too many cycles for a mechanical relay but no problem for solid-state.
This has to be a pretty simple analog circuit I can build with cheap Radio Shack parts right?
#83
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I'm not disagreeing here. Honestly, I'm having a hard time visualizing the effect of this arrangement. It will certainly contribute to turn-on lag, but I don't know what its steady-state characteristics will be. That's why I think a test will be valuable.
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Agreed. One good test is worth a thousand expert opinions. Give me a good circuit design and I should have it up and running pretty quick. I cannot work on this this weekend, but next weekend should be no problem.
#87
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Something like this would work: DPRG: A Simple PWM Circuit Based on the 555 Timer
#89
this is the datasheet for that FET: http://www.audiolabga.com/pdf/IRFZ46N.pdf
You will at least need a diode (unless you care to fry your headphone jack) and probably a 1k resistor as a load to make it switch to the headphone jack. I'm not sure what kind of signal you'll get out of it. You might want to use a scope to see what the app will produce and compare it to the FET datasheet.
You will at least need a diode (unless you care to fry your headphone jack) and probably a 1k resistor as a load to make it switch to the headphone jack. I'm not sure what kind of signal you'll get out of it. You might want to use a scope to see what the app will produce and compare it to the FET datasheet.
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Well I considered that but that is inconvenient for a few reasons. One I do not have a spare harness for it, and two, I do not have a means to stimulate it, like a jimstim or whatever the MS uses. I am not sure that I can get it to fire the outputs with the laptop tuning software with no trigger inputs. I am going to look into that though.
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Oh. I assumed that the Adaptronic could generate its own free-running sync pulses for injector testing like the MS2 can.
Even still, assuming it's currently wired up and running (the Adaptronic to the engine, I mean) you could just run the one extra wire for the HSV and simply extend the wire over to the bench. Have somebody hold the engine at a constant speed, set the HSV drive to whatever setting you want to test.
Even still, assuming it's currently wired up and running (the Adaptronic to the engine, I mean) you could just run the one extra wire for the HSV and simply extend the wire over to the bench. Have somebody hold the engine at a constant speed, set the HSV drive to whatever setting you want to test.
#93
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Oh. I assumed that the Adaptronic could generate its own free-running sync pulses for injector testing like the MS2 can.
Even still, assuming it's currently wired up and running (the Adaptronic to the engine, I mean) you could just run the one extra wire for the HSV and simply extend the wire over to the bench. Have somebody hold the engine at a constant speed, set the HSV drive to whatever setting you want to test.
#95
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I had a friend build me a very simple transistor circuit once that plugged into the headphone jack (audio signal) on a radar detector. No PCB board, just wires, solder, resistor, transistor can, maybe a diode, and shrink tubing. Built it in less than an hour with parts lying around the lab. It triggered a bright LED cluster whenever the radar beeped. I used it so I could see the radar detector go off when riding my bike (too loud to hear) and it worked great. I basically need a higher wattage version of the same thing. I'm tempted to use that setup but am thinking I might overload it.
Unfortunately that guy, an uber electronics tech, is not around here anymore so I can't tap his skillz for this. I was hoping one of you guys was uber enough to duplicate his deed
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Ok, here's what you do.
You've got the Adaptronic itself, right? Since it's not capable of doing something that a $200 ECU based on a 25 year old 8 bit microcontroller with 512 bytes of RAM can (Ok, that's the last one, promise), we'll help it along.
Hook the HSV up to the ECU. Configure it for a single 36-1 VR crankwheel. Then, download the software and build the circuit on this page: Crankshaft Timing Signal Wheel Simulator
For the transformer, you don't need to order from Digikey. RadioShack P/N 273-1380 will suffice. You can ignore the transistor and resistor- all you need is the 1/8" plug and the transformer.
With this, you can drive the Adaptronic to any RPM. I assume you know how to simulate various MAP conditions on it.
You've got the Adaptronic itself, right? Since it's not capable of doing something that a $200 ECU based on a 25 year old 8 bit microcontroller with 512 bytes of RAM can (Ok, that's the last one, promise), we'll help it along.
Hook the HSV up to the ECU. Configure it for a single 36-1 VR crankwheel. Then, download the software and build the circuit on this page: Crankshaft Timing Signal Wheel Simulator
For the transformer, you don't need to order from Digikey. RadioShack P/N 273-1380 will suffice. You can ignore the transistor and resistor- all you need is the 1/8" plug and the transformer.
With this, you can drive the Adaptronic to any RPM. I assume you know how to simulate various MAP conditions on it.
#99
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Good thing it has some other awesomeness to compensate for this relative weakness.
Hook the HSV up to the ECU. Configure it for a single 36-1 VR crankwheel. Then, download the software and build the circuit on this page: Crankshaft Timing Signal Wheel Simulator
For the transformer, you don't need to order from Digikey. RadioShack P/N 273-1380 will suffice. You can ignore the transistor and resistor- all you need is the 1/8" plug and the transformer.
With this, you can drive the Adaptronic to any RPM. I assume you know how to simulate various MAP conditions on it.
For the transformer, you don't need to order from Digikey. RadioShack P/N 273-1380 will suffice. You can ignore the transistor and resistor- all you need is the 1/8" plug and the transformer.
With this, you can drive the Adaptronic to any RPM. I assume you know how to simulate various MAP conditions on it.
#100
I am late to this discussion and am only here to offer a little info on PWM water delivery in the ag sector. Case IH uses it on their patriot sprayers. It is called AIM Command. It might give you some ideas. You set the pressure you want to deliver the liquid at and it adjusts the pw to match the desired spray volume vs speed.
Last edited by rweatherford; 02-05-2010 at 09:39 AM.