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need to build vss signal divider


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firedemonsic 
Member - Posts: 23
Member spacespace
Joined: September 09, 2011
Location: Virginia, United States
Posted: September 10, 2013 at 9:56 AM / IP Logged  
https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-frc1/1233481_719651408062024_2103913134_n.jpg
Final values for hfe were 80 and base current was .25mA
oldspark 
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Gold spacespace
Joined: November 03, 2008
Location: Australia
Posted: September 10, 2013 at 6:53 PM / IP Logged  
Not sure about your "CLOCK signal wire and grounded with a 480ohm resistor"...
But the simple solution is remove the LED from the input and run it off a unused 4017 output (0-3) instead.
If that flashes, why bother LEDing the clock?
firedemonsic 
Member - Posts: 23
Member spacespace
Joined: September 09, 2011
Location: Virginia, United States
Posted: September 10, 2013 at 7:35 PM / IP Logged  
Very true. And I discovered the issue was the VSS. Running the signal wire of the VSS to the clock wire resulted in a voltage drop across the whole CMOS. Running it to the main 12V supply line yielded full voltage across the CMOS.
I'm not sure if this is because the VSS doesn't have enough drive capacity or because an additional component was needed but I noted the outputs of the CMOS experienced this drop as well as the signal wire coming off the VSS. IIRC the CMOS output voltage is driven by Vcc so I suspect drive capacity of VSS is not the issue.
As for the transistor, sitting down? The CBE pin layout on the transistor is as the transistor is viewed from the bottom. However, I was viewing it from the TOP, so that means I got the collector and emitter connections reversed.
This is why I HATE doing these types of projects when I'm dog tired...
firedemonsic 
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Member spacespace
Joined: September 09, 2011
Location: Virginia, United States
Posted: September 10, 2013 at 8:24 PM / IP Logged  
BTW as for input LED going to another output pin.
What I wanted the LEDs for was so that I could watch the signal wire going to the ECM (Output of CMOS) to flash for every 4 pulses recieved at the CLOCK pin so I watch the division going on.
At this point I however I just desoldered the input LED and resistor from the board. Output pulse LED (2kppm) is good enough for me. At this point I'm more tired of driving around with no cluster than anything and just want it finished.
Maybe with the "But the simple solution is remove the LED from the input and run it off a unused 4017 output (0-3) instead.
If that flashes, why bother LEDing the clock?" you are referring to keeping track of the OUTPUT pulse which makes perfect sense and I don't know why I overthought this to begin with and went with the transistor route. Hey it did teach about transistors however...
For the input pulse LED, it would have to be connected to CLOCK otherwise it would not light up every time a pulse was received from the VSS.
oldspark 
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Gold spacespace
Joined: November 03, 2008
Location: Australia
Posted: September 11, 2013 at 2:41 AM / IP Logged  
I knew what you wanted (seeing the 4:1) but since it caused so much trouble. And I know I have sometimes gotten carried away with the "need" to see input signals when really I don't have to.
Still, if input was wanted, did I mention MOSFETS? (LOL). Otherwise a 2nd transistor to provide another ~80x amplifiction between the clock & LED tranny's Base.
I find it strange that the VSS should "bring the 4017" voltage down, but maybe you mean just the input and not the whole 4017 (ie, its +V supply of ~12V).
But keep in mind that many such pulse outputs (from Halls & Optics) are Open Collector and hence only connect to 0V/GND. Hence their output would be to the 4017 clock input - maybe through a series resistor (say 1k?) with a resistor to the 4017's +V.
Re the 1k? - let's see - 4017 CLK requires less than 1uA @ 7V (assuming Vdd = 10V); V=IR hence R=V/I = (10-7)V/1uA = 3V/1uA = 3M, hence again a 100K resistor should be fine, or less (19k, 1k, etc). But that series resistor should be much bigger than the pull-up resistor (from VSS to +V) - I'd suggest at least 10x, a pull up of 1k with series of 10k or 100k should be fine. (The pull-up and input-series resistor form a voltage divider so a 1:10 ratio means less then 1/10th voltage loss; 1:100 means < 1/100th loss etc.)    
firedemonsic 
Member - Posts: 23
Member spacespace
Joined: September 09, 2011
Location: Virginia, United States
Posted: September 11, 2013 at 3:14 PM / IP Logged  
Next time I will definitely try the FET route.
https://sphotos-b-iad.xx.fbcdn.net/hphotos-ash4/1174922_720416857985479_1763848878_n.jpg
http://www.youtube.com/watch?v=D83dlj-P53Q&feature=youtu.be
Thank you my friend. You have been extremely helpful need to build vss signal divider - Page 3 - Last Post -- posted image.
oldspark 
Gold - Posts: 4,913
Gold spacespace
Joined: November 03, 2008
Location: Australia
Posted: September 11, 2013 at 11:02 PM / IP Logged  
Te-bluddy-riffic! I love it when it all comes together (especially with P1's etc!... if it does the job, why not?)
I like it too when "a site" does not get to censor naughty words... need to build vss signal divider - Page 3 - Last Post -- posted image. need to build vss signal divider - Page 3 - Last Post -- posted image.
I like your circuit too. The 4017 is great for division by whole numbers (2-10; or cascaded for higher multiples) and easy by simply remembering that "Reset = Qn output" where n = the divide by count, AND provided the first output is Q0 (not Q1 as some denote).
One triviality, I'll usually chose an output other than Q0 because Q0 is the default on after a reset - not that I'm sure if the 4017 powers up in that state (maybe the user has add an RC to the Reset pin to ensure that), and not that it matters for typical counter/div circuits like this (since downstream counters are usually edge triggered, and so what if they miss the first pulse?).
I'll use Q0 when used for multi-position pulsed switches - eg, low-high dippers (divide by 2) etc.
[ Yeah, isn't the 4017 overkill for a simple div by 2? But SAAB and others use it for their hi/low dipper circuits. Why not? Simple, guaranteed start up on low beam (Q0 assuming a POR (Power-On Reset) circuit or behavior), and easy to expand for more outputs. ]
Now for a 8700 divided by 4.35 circuit...
[ LOL - maybe my 1970's "electronic Halda" circuit. Nobody told me that electronic Haldas (accurate odometers used for rallying) were "impossible" so I built one. About 5 speedo cable pulses for 10m (else 10 yards - the Halda resolution) so each triggered 200 pulses (using 2 555 timers) and then 3 cascaded 4017s with decimal thumbwheel switches between each 4017 so that whatever divide-by count between 2-999 could be set to achieve the (generally) better than 1% accuracy required. ]
These days I'd use an 8-pin PICAXE 08M2.
PS - I forgot to say your image file names are too long. They have to be under ~10 characters. Do a "Preview Post" before Updating Post to check that they appear.
davep. 
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Gold spacespace
Joined: May 27, 2011
Location: California, United States
Posted: October 08, 2013 at 1:38 AM / IP Logged  
How about a different approach?
I don't know what the intelletronics VSS sensor is. I couldn't find any description on their website. But I suspect it is a mechanical generator driven by the mechanical output on the transmission. IE, you did not open the transmission and convert it to a tone-wheel VSS like later vehicles with electronic speedometers.
I propose that you select a cable driven 2-pulse generator, and a suitable buffer to output the needed signals for the cruise and ECM. H here's a .pdf from Jags That Run. they have been producing engine swapping manuals for EFI engines since 1991. They have a lot of information regarding EFI and VSS on their site, and in their manuals.
#1 would below would out put the correct signal for the eCM and cruise for a 1985 TPI engine. The .pdf describes each item pictured below.
Read the .pdf. You may be able to do it simpler with factory parts.
need to build vss signal divider - Page 3 - Last Post -- posted image.
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