DIY_EFI Digest Sunday, 18 February 1996 Volume 01 : Number 046 In this issue: Re: Looking for low-cost ignition analysis 'scope AMD9513 timer chip MPX2200 Re: MAP Questions... Re: Sound Blaster as Data Aquisition See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: jhawken@xxx.com (Jason Hawken) Date: Sat, 17 Feb 1996 09:52:51 -0500 (EST) Subject: Re: Looking for low-cost ignition analysis 'scope >This is something I have been wanting to do for a while as I find it >fastinating that you can assess an engine's condition just by looking at >the spark waveforms. > >I have tried he approach of using a "Lab" scope with the inductive pickup >from my timing ligt for trigger and a piece of metal over the coil in the >middle of the GM HEI distributor (this is the way the Heathkit analyser >works as well as other prfessional units I have seen). The interfacing is >not a problem, where I ran into problems is that the repitition rate of the >signals from the engine are so slow at idle that the scope does not have >enough persistance to keep the display on the screen. When I did this >(about 10 years ago) I used a Tek 465 100Mhz scope maybe a lesser scope >would be better but I doubt it because the signal is pretty slow (600 RPM = >10 RPS /2 = 5 triggers per second). Well is what you need is a new scope with a write feature. With this feature, the scope will keep the display on the screen even after it has disappeared! CFN:JH +------------------------------------------------------------+ + Jason Hawken Ottawa, ON + + jhawken@xxx.com (613) 728-9043 + +------------------------------------------------------------+ ------------------------------ From: jsturs@xxx.nl (Jim Sturcbecher) Date: Sat, 17 Feb 1996 17:44:16 -0100 Subject: AMD9513 timer chip On Fri, 16 Feb 96 17:34:13 EST Will McGonegal wrote: >They also have several other cards, some that are only digital input or >output, isolated digital IO, analog output, timer cards (using the AMD >am9513 chip; much better than an 8253 or 8254), etc. > just a side note; AMD no longer manufacture the 9513 unfortunately, and there is no replacement. I loved that chip for its versatility. Jim Sturcbecher jsturs@xxx.nl ------------------------------ From: ducharme@xxx.com (CF Ducharme) Date: Sat, 17 Feb 96 13:07:55 EST Subject: MPX2200 ------------------------------ From: dn Date: Sat, 17 Feb 96 12:29:18 MDT Subject: Re: MAP Questions... Jim Staff writes: > I don't know how to make a Throttle Position Sensor, But I'm sure > somebody here know or I could find it out god knows I've found out > impossible stuff already. Jim, head down to your local auto parts store and ask the guys behind the counter to have a look at a Standard Motor Products or Echlin emission controls catalog. These have nice little pictures of a zillion different types of throttle position sensors, I'm sure you could find one to fit your application. It's just a pot, hook the ends to 5V and ground and read the voltage at the wiper to get throttle position. Resist the temptation to just use a 99 cent pot from your local Radio Shack, they are not made for the constant dithering and movement that a TPS sees. Once you get this data, you're on your own... > calculation, and make a TPS. I pray to god my op amp thing works or i'll kill > myself, along with a relatively expensive MPX2200 sensor. See my reply in diy_efi subject "Lawnmower Man". It was originally targeted to another guy doing a B+S conversion, I didn't realize until just now that there were two of you. Jeeze, now ya got me contemplating hopping up the old garden cultivator... regards dn - -- - --------------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Bang: calgary!debug!dlogtech!darrell Calgary, Alberta, Canada Voice: +1 (403) 243-2220 Fax: +1 (403) 243-2872 @ + < __/ "Absolutum Obsoletum" - If it works, it's obsolete -------------------------------------------------------------------- ------------------------------ From: dn Date: Sat, 17 Feb 96 12:38:25 MDT Subject: Re: Sound Blaster as Data Aquisition Mark Boxsell wrote: > Yes! ,This is exactly what I was wondering maybe we all have a > digital storage cro in our PC's after all! Has anyone out there seen any > articles on this, I think the 'line in' accepts 0 - 250mV so you would have > to put a front end of some kind on the thing. > Whoever works out a kit for this will make a fortune. I don't have time at > the moment so someone else will have to do it! The main problem with a sound blaster card is that it doesn't accept DC signals. The inputs are capacitor coupled so they block DC. I think it will go down to about 10Hz minimum frequency. It is made to digitize audio, which probably wouldn't work for most sensor type inputs 'cause they're mainly a slow changing DC signal. I have used a sound blaster with some nifty software which gives you a spectrum analyzer and sort-of-oscilliscope, but the limitations on bandwidth, etc make it iffy for other applications. If your'e doing Audio work, its' great, because after all that's what the card was designed for... regards dn - -- - --------------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Bang: calgary!debug!dlogtech!darrell Calgary, Alberta, Canada Voice: +1 (403) 243-2220 Fax: +1 (403) 243-2872 @ + < __/ "Absolutum Obsoletum" - If it works, it's obsolete -------------------------------------------------------------------- ------------------------------ End of DIY_EFI Digest V1 #46 **************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".