DIY_EFI Digest Thursday, 4 February 1999 Volume 04 : Number 089 In this issue: Re: Tim Drury article Re: fusible link questions Re: Groan... Not another VIRUS alert.... Re: Chevy ECMs Re: 808 Request [announce] gmecm Re: PWM motor controller Re: PWM motor controller RE: Intake Runner Length Re: Groan... Not another VIRUS alert.... RE: fusible link questions Re: fusible link questions Re: superchargers for <$1500? Got one. rev2, PWM controller Re: fusible link questions Re: fusible link questions Re: fusible link questions RE: Intake Runner Length Re: Groan... Not another VIRUS alert.... Re: Intake Runner Length Re: fusible link questions MAP manipulations Re: Intake Runner Length 92 tracker ecm Re: PulseWidthModulation comments High swirl port design Re: PulseWidthModulation comments Re: DIY_EFI Digest V4 #85 Re: fusible link questions RE: PulseWidthModulation comments Re: Intake Runner Length Re: DIY_EFI Digest V4 #85 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Tom Parker" Date: 05 Feb 99 01:02:56 +1200 Subject: Re: Tim Drury article Clarence L.Snyder wrote: >-- >> > From: wmcdonal@xxx.au] >> > Sent: Wednesday, February 03, 1999 7:46 AM >> > To: 'diy_efi@xxx.edu' >> > Subject: RE: Tim Drury article >> > >> > I have a copy of the article and can scan/ocr it in if anyone needs it. >> > >> > Wayne. >> > >Send me one too, please. I have the article as it was presented from the link on the diy_efi homepage I have everything, the postscript files, graphics and html. I've put it on my web page as a zip file. - -- Tom Parker - tparker@xxx.nz - http://www.geocities.com/MotorCity/Track/8381/ ------------------------------ From: Pat Ford Date: Thu, 4 Feb 1999 08:51:35 -0500 Subject: Re: fusible link questions On Thu, 4 Feb 1999, Steve Sassine wrote: > Date: Thu, 4 Feb 1999 16:43:22 +1100 (EST) > From: Steve Sassine > To: DIY_EFI@xxx.edu > Subject: Re: fusible link questions > > On Wed, 3 Feb 1999, Clive Apps Techno-Logicals 416 510 0020 wrote: > > > > > > > The fusable link is intended to protect the wiring harness from frying - > > > through out the vehicle. It is the weakest link in the wiring 'chain'. They > > > normally have a high temperature insulation that also protects any adjacent > > > wires from being burned. > > > > Clive > > SNIP > a large amount of current will be deleivered to the field winding which > will inturn give an output voltage well in excess of 20V plus. This > voltage level will take out many electronic equipment > (radio,alarm,electronic wind screen controller etc.). Canadain tire used to sell a box that would output 120 vdc from the alternator. it just full fielded the alt and at around 1500 rpm 120 v scarry eh > > I have seen this happen on a toyota corona, but some of the > devices are fused seperatly to protect against high voltages. > > > Pat Ford email: pford@xxx.com QNX Software Systems, Ltd. WWW: http://www.qnx.com (613) 591-0931 (voice) mail: 175 Terrence Matthews (613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8 ------------------------------ From: Will McGonegal Date: Thu, 04 Feb 1999 09:29:23 -0500 Subject: Re: Groan... Not another VIRUS alert.... I checked a virus information library at http://vil.mcafee.com/villib/query.asp and got to the page: http://beta.nai.com/public/datafiles/valerts/vinfo/w32ska.htm and the HAPPY99.EXE is apparently a worm that attaches to e-mail that can spread itself. The document says that it does check for items on your computer, adds files, changes the registry and will attach itself to outgoing mail. Will ------------------------------ From: Ken Kelly Date: Thu, 04 Feb 1999 09:39:35 -0500 Subject: Re: Chevy ECMs Dave, My PCM is an 16188051. It was used in the buick, but I think only with the LT1 engine. As far as I know all 95 GM's with the LT1 used this PCM. I think all 95 leSabre's were V-6? If yours is a 16188051, then my prom images should work in it for use with the LT-1. The Lt1 engine had Eprom only in 93. from 94 up they used Flash memory or EEprom. The Flash in mine is a 28F512. There are actually two chips. one with EVENT code, the other with TIMING code. I often see them refered to as the engine, and transmission proms, but that isn't really true. They are event and timing. If you are going to try to play with it let me know. I can probably help a little. Gm Scrambled the Flash memory, We have figured it out for the 8051, it my be the same on yours. If it is an 8051, I am very interested in working with you. Ken David A. Cooley wrote: > > At 09:43 AM 2/3/99 -0500, you wrote: > >Ernst, > > > >I haven't disected a 96 unit, so I can't give you a direct > >answer. They seem to be very similar in many respects. I > >have my 95 apart, socketed the PCM, and I am building a > >Flash prom editor for this beast. If someone with a 96 wants > >to open his or hers we can compare notes. > > > Ken, > What car is your 95 PCM from? > I have an extra I'm dissecting for my 95 LeSabre... > Still has a mem-cal, but has EEprom as well (I think...) > > =========================================================== > David Cooley N5XMT Internet: N5XMT@xxx.net > Packet: N5XMT@xxx. Member #7068 > I am Pentium of Borg...division is futile...you will be approximated. > =========================================================== ------------------------------ From: Ken Kelly Date: Thu, 04 Feb 1999 09:44:04 -0500 Subject: Re: 808 Request Jon, Where are you located. I'm in Northern NJ and have an Eprom Burner & eraser. If you have the image you want installed & the chip to install it in I can do it for you. Ken Jon Fedock wrote: > > Hello All, > I have a request, hopefully someone here can help me out. I have 2 > vehicles that I have transplanted TPI into. One is a 305/t-5 and the other > is a 350/700r. I have a bad MAF on the 305, and would like to use this as an > excuse to change over to a MAP style setup to eliminate some of my plumbing > nightmare. Since I am using the 165 ECM, I am thinking of using a 808 > calibration (ASBX ?). As I understand it, ASBX was for a 5.0L motor, so it > should be pretty close? I can hadle the wiring differences. But not the > Eprom. This is where it gets tricky. I don't have (or have access to) an > EPROM burner. Would anyone on the list be willing to burn the required chip? > I will pay for time, shipping, the chip itself, etc. > Or, would I be better off to just go and get a 730 and a Memcal for a > comparable Camaro/Firebird (More $$$)? My plan is to eventually put MAP on > the other car also, but I know the calibration is probably too far off. One > step at a time. > Thanks for any input or correction, > Jon Fedock ------------------------------ From: jgwynne@xxx.com Date: Thu, 04 Feb 1999 10:17:14 -0500 Subject: [announce] gmecm I've created the mailing list "gmecm" that I hope will be a forum where we can examine more closely the inner working of a number of GM ECMs. Let's subscribe now but wait a few days before posting... just to give everyone time to subscribe. Let say Tuesday. john ============================================================ To subscribe: Send to Majordomo@xxx.edu subscribe gmecm [your email address *only* if different than your "From" address] To unsubscribe: Send to Majordomo@xxx.edu unsubscribe gmecm [your *registered* email address if different than your "From" address] For help: Send "help" to Majordomo@xxx. To post: Send to "gmecm@xxx.edu" Digest mode: This is available for all of the mailing list. Send "lists" to Majordomo for a listing a mailing lists served. To switch to the digest mode, unsubscribe to the regular list and then subscribe to the digest version (i.e., gmecm-digest). Charter: (subject to change...) This mailing-list is *strictly* dedicated to the discussion of topics related to OEM ECMs design and modification. ------------------------------ From: rauscher@xxx.com Date: Thu, 04 Feb 99 10:21:36 -0500 Subject: Re: PWM motor controller The 470uf is mentioned in the writeup, it is not on the schematic. It has to do with filtering on the pump motor itself. It's purpose is to provide a local low impedence source of power for when the motor is turned on. Each motor is different, through experimenting, you may find that it's not needed, to needing to be larger... BobR. >(snip) >>>4. 470 uf 25V -- only electrolytic ??? >> >>Electrolytic is fine, and cheap. >> (big snip) Clarence wrote: > I am lost on this one! The only 470 I can find on the schematic is a resistor. Where is the 470 uf >capacitor used? > >Clarence ------------------------------ From: rauscher@xxx.com Date: Thu, 04 Feb 99 10:25:54 -0500 Subject: Re: PWM motor controller Clarence wrote: > Thanks for the info! I am planning to use the circuit for cooling fan control; will use water teperature >sender instead of 5k pot; is there anything wrong with doing that? I don't think you will be able to use the temp sender directly. But through the creative use of 'other' electronics, yep, it's do-able. You will just need to scale the sender resistance into a voltage that can be used to control the PWM driver. BobR. - -- ------------------------------ From: rauscher@xxx.com Date: Thu, 04 Feb 99 10:43:01 -0500 Subject: RE: Intake Runner Length >Exactly right! We have been playing around with different porting schemes >and found that you don't want the air to tumble in around the valve, >instead, if you can make it swirl in (Vortec's idea?) you can get a lot more >in. "Some" drag-racers claim that you want the swirl to go ccw also. (Why, >and for what purpose? I can't imagine). We haven't got to playing with Simple, north of equator, CCW, for our Aussie friend's, it's CW >square or rectangular runners yet. Our cyl-to-bore ratio is 82%. (It's >easier to turn up the boost to get more). >Good input, thanks.....Tim. BobR. - -- ------------------------------ From: Teller.John@xxx.com Date: Thu, 4 Feb 1999 10:42:14 -0500 Subject: Re: Groan... Not another VIRUS alert.... OK. I apologize for my offhand dismissal of the warning but I've been innundated in the past by well intentioned people spreading warnings of imminent "end of the world" type virii that can infect any computer (PCs, Macs, Unix boxes, Amigas, Commodore 64s, etc.). This worm is pretty sophisticated. Like most worms, it only attacks one sort of operating system (Windows 95) on a particular machine (PC), because it takes advantage of a security hole that does not exist on other operating systems. It looks like this worm would also attack Windows 98, since that OS is really only an update to W95. Unlike the famous worm that brought down the internet in the mid-80's, this one won't launch itself when the email it is attached to is read... - --- John Teller ------------------------------ From: rauscher@xxx.com Date: Thu, 04 Feb 99 10:46:06 -0500 Subject: RE: fusible link questions Clarence wrote: > Just installed a 100 amp altenator and the guy at the shop who sold me the unit told me to run a line >of fusible link (14 Ga) from the Bat. terminal on the alternator to the positive terminal of the batery. The >length of fusible link needed was about 4 ft. long. Should I have ran a 3ft 9in wire of 10 Ga and then >soldered in a 3 inch piece of 14 Ga fusible link? > >Clarence Correct, max length of a fusible link is 9 inches, from the GM manual. And as mentioned previously, 4 AWG numbers smaller than wire to protect. BobR. - -- ------------------------------ From: KD6JDJ@xxx.com Date: Thu, 4 Feb 1999 10:48:48 EST Subject: Re: fusible link questions The fusiable link has two purposes, firstly to protect the alternator from over loading, and to protect sensitive electronic equipment installed in the engine. The battery can still be over charged with out blowing the fusilble link. What am I missing here??? I assume that the alternator + is connected to the battery + using 1 wire. I assume that the wire is big enough to deliver ALL the current that the produce. The windings in the stator will establish that current limit. When would a "systems designer" connect vonerable(spelling?) sensitive electronic devices to any part of that ? I suggest that the biggest 'practical' wire be used to connect the alternator to the battery. If I am wrong with this 'advice' , please inform me. But please bring some facts , or at least some actual experiences. Jerry ------------------------------ From: Daniel Ciobota Date: Thu, 04 Feb 1999 10:12:24 -0600 Subject: Re: superchargers for <$1500? Got one. Folks, if anyone here needs a 79-93 mustang supercharger, I've got one for sale and it's only $1300. It's made by Powerdyne, and it's belt driven, externally and internally; it's extremely quiet. It puts out 9lb boost on a 302cid motor, and it's very easy to fabricate a bracket for the head unit (it's a centrifugal type) to fit other cars. The kit comes complete, including original instructions, brackets, tubes and fmu. There are no oil lines to plumb, as the unit has ceramic dry bearings. Daniel Clive Apps Techno-Logicals 416 510 0020 wrote: > > > > > > > > > but used chargers to fit a Mustang or GM Fbody are relatively easy to find > > > used > > > > Know of any in particular? > > Paxton, Vortec, Whipple > > Is it wise for one to buy a used super > > charger? > > if you trust the person you are buting from no probelm > or if you buy from someone on a list you know > price for a complete used unit in VGC is approx $ 1500 US > > Can they be rebuilt? > > most the manuf will sell kits or rebuild and upgrade for you > > Clive ------------------------------ From: rauscher@xxx.com Date: Thu, 04 Feb 99 11:30:39 -0500 Subject: rev2, PWM controller OK, placed the new write-up and schematic in the 'incoming' directory. Please get the new write-up also, I've added to it. pwm2.txt and pwm2.gif (note case). Very little changed, mostly the addition of a variable regulator to the PWM control circuits. Once on the bench, I found that the actual range of the control volts (Vin), was less than I anticipated. (I'm not a EE either, thou sometimes I play one). The vari-reg will allow the range to be adjusted. BobR. - -- ------------------------------ From: Pat Ford Date: Thu, 4 Feb 1999 11:57:17 -0500 Subject: Re: fusible link questions On Thu, 4 Feb 1999 KD6JDJ@xxx.com wrote: > Date: Thu, 4 Feb 1999 10:48:48 EST > From: KD6JDJ@xxx.com > To: diy_efi@xxx.edu > Subject: Re: fusible link questions > snip > > What am I missing here??? > I assume that the alternator + is connected to the battery + using 1 wire. > I assume that the wire is big enough to deliver ALL the current that the > produce. The windings in the stator will establish that current limit. the regulator controls current output, current input is limit only by the diodes (as someone else pointed out) Gm and Ford both use fusible links between batt and alt. they screw with safty to save pennies a car but still have an alt fuse or fuse link > > When would a "systems designer" connect vonerable(spelling?) sensitive > electronic devices to any part of that ? every day? I think I know what you are trying to say pls correct me if I'm wrong but are you saying that the battery is capable of acting as a buffer? > > I suggest that the biggest 'practical' wire be used to connect the > alternator to the battery. If I am wrong with this 'advice' , please inform > me. But please bring some facts , or at least some actual experiences. 77 mercury s/w 460 cid fuse link fatigued car wouldn't charge 76 honda upgraded to delco alt (100 amp for sterio sys) blew fuse no charge 84 subaru 1.8l delco alt for sound system blew fuselink ... it is a common to fuse this wire ( as a dealership mechanic alot of charging problems were the fuse/fuselink popping and distroying the alternator) > > Jerry > Pat Ford email: pford@xxx.com QNX Software Systems, Ltd. WWW: http://www.qnx.com (613) 591-0931 (voice) mail: 175 Terrence Matthews (613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8 ------------------------------ From: Clarence Wood Date: Thu, 04 Feb 1999 11:07:48 -0600 Subject: Re: fusible link questions If you are referring to my original post, I have gone from a 60 amp to a 100 amp alternator. To make sure that the original + wire from the alt. to the battery wouldn't overload, the suggestion was made (not by anybody on this list) to run another wire from the + post on the alt. to the + post on the battery. The original suggestion was to use 14 Ga fusible link, 4ft long. I am instead going to use 3ft 9 in of 10 Ga wire and then attach 3 in of 14 Ga fusible link. Clarence At 10:48 AM 2/4/99 EST, you wrote: >The fusiable link has two purposes, firstly to protect the alternator >from over loading, and to protect sensitive electronic equipment >installed in the engine. The battery can still be over charged with out >blowing the fusilble link. > > What am I missing here??? > I assume that the alternator + is connected to the battery + using 1 wire. > I assume that the wire is big enough to deliver ALL the current that the >produce. The windings in the stator will establish that current limit. > > When would a "systems designer" connect vonerable(spelling?) sensitive >electronic devices to any part of that ? > > I suggest that the biggest 'practical' wire be used to connect the >alternator to the battery. If I am wrong with this 'advice' , please inform >me. But please bring some facts , or at least some actual experiences. > > > Jerry > > ------------------------------ From: "Clive Apps Techno-Logicals 416 510 0020" Date: Thu, 4 Feb 1999 12:16:31 -0500 (EST) Subject: Re: fusible link questions > > On Wed, 3 Feb 1999, Clive Apps Techno-Logicals 416 510 0020 wrote: > > > > > > > > > > The fusable link is intended to protect the wiring harness from frying - > > > > through out the vehicle. It is the weakest link in the wiring 'chain'. They > > > > normally have a high temperature insulation that also protects any adjacent > > > > wires from being burned. > > > > > > Clive > > > > SNIP > > a large amount of current will be deleivered to the field winding which > > will inturn give an output voltage well in excess of 20V plus. This > > voltage level will take out many electronic equipment > > (radio,alarm,electronic wind screen controller etc.). > > Canadain tire used to sell a box that would output 120 vdc from the > alternator. it just full fielded the alt and at around 1500 rpm 120 v > > scarry eh > > > > > I have seen this happen on a toyota corona, but some of the > > devices are fused seperatly to protect against high voltages. > > I have one of those cantire boxes here someone gave it ot me nebver hooked it up though may be useful on my 4X4 somtime, should think abotu trying it Clive ------------------------------ From: "Van Setten, Tim (AZ75)" Date: Thu, 4 Feb 1999 10:13:52 -0700 Subject: RE: Intake Runner Length > ---------- > From: rauscher@xxx.com] > Reply To: diy_efi@xxx.edu > Sent: Thursday, February 04, 1999 8:43 AM > To: DIY_EFI@xxx.edu > Subject: RE: Intake Runner Length > > > > > >Exactly right! We have been playing around with different porting > schemes > >and found that you don't want the air to tumble in around the valve, > >instead, if you can make it swirl in (Vortec's idea?) you can get a lot > more > >in. "Some" drag-racers claim that you want the swirl to go ccw also. > (Why, > >and for what purpose? I can't imagine). We haven't got to playing with > > Simple, north of equator, CCW, for our Aussie friend's, it's CW > BobR. > Ok, I understand the Coriolis Force effect, but do you think it really makes a difference? Especially at the speed the air is traveling??? Tim. ------------------------------ From: EFISYSTEMS@xxx.com Date: Thu, 4 Feb 1999 12:28:34 EST Subject: Re: Groan... Not another VIRUS alert.... Hi all, I found a Happy.exe(no 99 though) on my old computer and it has been there almost a year and I haven't seen any trouble from it.....but I use Win 3.1 on that one so maybe that explains it......is there anything I should check for????TIA - -Carl Summers In a message dated 2/4/99 7:56:03 AM Pacific Standard Time, Teller.John@xxx.com writes: << Subj: Re: Groan... Not another VIRUS alert.... Date: 2/4/99 7:56:03 AM Pacific Standard Time From: Teller.John@xxx.com Sender: owner-diy_efi@xxx.edu Reply-to: diy_efi@xxx.edu To: diy_efi@xxx.edu OK. I apologize for my offhand dismissal of the warning but I've been innundated in the past by well intentioned people spreading warnings of imminent "end of the world" type virii that can infect any computer (PCs, Macs, Unix boxes, Amigas, Commodore 64s, etc.). This worm is pretty sophisticated. Like most worms, it only attacks one sort of operating system (Windows 95) on a particular machine (PC), because it takes advantage of a security hole that does not exist on other operating systems. It looks like this worm would also attack Windows 98, since that OS is really only an update to W95. Unlike the famous worm that brought down the internet in the mid-80's, this one won't launch itself when the email it is attached to is read... --- John Teller >> ------------------------------ From: ECMnut@xxx.com Date: Thu, 4 Feb 1999 13:11:37 EST Subject: Re: Intake Runner Length This is not making sense. The "corkscrew" ports on the intake side of my Syclone's votec heads are generally considered to be bad. The faster guys use the earlier 229 (regular intake port), or the bowtie heads, which don't use that vortec crap.. It seems to be good at making low to midrange torque with surprisingly little spark advance, but useless for big flow or high RPM... any thought would be appreciated. MNike V >Exactly right! We have been playing around with different porting schemes >and found that you don't want the air to tumble in around the valve, >instead, if you can make it swirl in (Vortec's idea?) you can get a lot more >in. "Some" drag-racers claim that you want the swirl to go ccw also. (Why, >and for what purpose? I can't imagine). We haven't got to playing with ------------------------------ From: Pat Ford Date: Thu, 4 Feb 1999 13:37:07 -0500 Subject: Re: fusible link questions On Thu, 4 Feb 1999, Clive Apps Techno-Logicals 416 510 0020 wrote: > Date: Thu, 4 Feb 1999 12:16:31 -0500 (EST) > From: Clive Apps Techno-Logicals 416 510 0020 > To: diy_efi@xxx.edu > Subject: Re: fusible link questions > > > > > On Wed, 3 Feb 1999, Clive Apps Techno-Logicals 416 510 0020 wrote: > > > > > > > Canadain tire used to sell a box that would output 120 vdc from the > > alternator. it just full fielded the alt and at around 1500 rpm 120 v > > > > scarry eh > > > > > > > > I have seen this happen on a toyota corona, but some of the > > > devices are fused seperatly to protect against high voltages. > > > > > > I have one of those cantire boxes here > someone gave it ot me > nebver hooked it up though > may be useful on my 4X4 somtime, should think abotu trying it be sure that you add a resistor to load the field output from the regulator ( I think that these boxes were designed for the old mechanical regulator) A friend and I went through a handful of regulators before I figured that out. watch how fast the output volts go up with rpm > > Clive > Pat Ford email: pford@xxx.com QNX Software Systems, Ltd. WWW: http://www.qnx.com (613) 591-0931 (voice) mail: 175 Terrence Matthews (613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8 ------------------------------ From: "Falb, John" Date: Thu, 4 Feb 1999 13:37:50 -0500 Subject: MAP manipulations Are there any current designs or thoughts on modifying the output of a 5v MAP sensor.   1. Moving the output up or down by a fixed amount over the entire operating range.   2. Change the gain of the output up or down.   3. Not letting the output exceed 5v.   An example of one is here but it costs 300 and 500 respectively. http://www.splitsec.com/products/arc1/arc1ds.htm http://www.splitsec.com/products/arc2/arc2ds.htm   If you have any ideas please share.   John Falb ------------------------------ From: "Bruce Plecan" Date: Thu, 4 Feb 1999 14:20:57 -0500 Subject: Re: Intake Runner Length - -----Original Message----- From: ECMnut@xxx.com> To: diy_efi@xxx.edu> Date: Thursday, February 04, 1999 1:27 PM Subject: Re: Intake Runner Length Dog leg ports, ain't bad. The best head on our tractor has a big dog leg in them. This is on a direct injection engine (fuel shoot in cylinder), and it realllllyyyyyyyyy works. There are soo many wife's tales, rumors,and lies about port shapes. The other day I mentioned Yates probably being over the 85% number. Looks like he might be at 91%. Bruce Doc is on a exercise program...... Beating his head against a wall is 150 calories per hour....... >This is not making sense. The "corkscrew" ports on the intake side of >my Syclone's votec heads are generally considered to be bad. >The faster guys use the earlier 229 (regular intake port), >or the bowtie heads, which don't use that vortec crap.. > It seems to be good at making low to midrange torque >with surprisingly little spark advance, but useless for >big flow or high RPM... any thought would be appreciated. >MNike V > >>Exactly right! We have been playing around with different porting schemes >>and found that you don't want the air to tumble in around the valve, >>instead, if you can make it swirl in (Vortec's idea?) you can get a lot more >>in. "Some" drag-racers claim that you want the swirl to go ccw also. (Why, >>and for what purpose? I can't imagine). We haven't got to playing with > ------------------------------ From: Pat Ford Date: Thu, 4 Feb 1999 14:22:23 -0500 Subject: 92 tracker ecm Hi All do any of you know what ecm my tracker uses ( if it's a gm or suzuki) thanks Pat Ford email: pford@xxx.com QNX Software Systems, Ltd. WWW: http://www.qnx.com (613) 591-0931 (voice) mail: 175 Terrence Matthews (613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8 ------------------------------ From: rauscher@xxx.com Date: Thu, 04 Feb 99 14:20:40 -0500 Subject: Re: PulseWidthModulation comments Ludis wrote: >Years ago as a summer intern I worked on a motor controller which used >PWM. A brushless DC motor ran on up to 120 to 170 volts at up to 10 to >15 amps. A switching (PWM) power supply controlled the voltage applied >to the motor. >An improved version used a microcontroller controlled digital PWM. I >think the PWM frequency was about 20 KHz and the PWM had 5 bits of >range. The same microcontroller monitored the motor position/speed to >form a closed loop system. Was this motor designed specifically for this freq? When I first developed this PWM motor controller, I was trying to run it at 20KHz also. But the motor was down on power. Motor was an AstroFlight cobalt, 9.6V at 35Amps, such as those used in R/C model aircraft. Going to the lower freq brought the power back up. I looked at possibly skin effect, but the wire used in the winds wasn't that large. >Some comments applicable to fuel pump / coolant fan PWM control: > >The pulse width and frequency needs to be very stable, otherwise all the >inductors in the circuit will squeal like stuck pigs. The original >analog system screamed constantly. The digital system (running the same >switcher!) was totally silent as long as the pulse width wasn't >changing. Software in the microcontroller updated the pulse width every >millisecond. When the pulse width needed to be changed often, this >produced a 1 KHz tone from the electronics. The amount of noise was >directly proportional to the load on the motor. You could actually hear >the computer "straining" against a high load. Sounds as thou the noise is from the P/S, and not the motor. I've only heard a light whine from the motors, and only at lower speeds. So hopefully the noise won't be enough to drive folks out of the car . >The main switching transistor was a TO-220 package mounted on a dinky >little heat sink. You don't need a massive TO-3 transistor. In the >above system, cooling the rectifier diodes was actually more of a problem. Oh so true, in the writeup I showed that even at 15 Amps, the MOSFET only needed to dissipate a little more than 5 watts. Only a small heat sink required. The key to the proper MOSFET, is low voltage drop through it. This keeps losses down and heat also. >BTW, in one mode, this motor was reversed every several tenths of a >second. This applies to a thread from several weeks ago. My brain is fading here, possibly relative to a motor driven FPR? BobR. - -- ------------------------------ From: EFISYSTEMS@xxx.com Date: Thu, 4 Feb 1999 14:31:38 EST Subject: High swirl port design Hi Mike, The high swirl dog leg in your head is great for low speeds but only allows the air to drop into the cylinder 1 inch(for a number),,,,whereas a port that isn't as high swirl will send the air into the cylinder farther, therefore better cylinder filling at high rpm.....I know yours is a boost application and isn't as touchy about this as aspirated is but still applies......hth's - -Carl Summers ------------------------------ From: Roger Heflin Date: Thu, 4 Feb 1999 13:36:24 -0600 (CST) Subject: Re: PulseWidthModulation comments On Thu, 4 Feb 1999 rauscher@xxx.com wrote: > > Ludis wrote: > >Years ago as a summer intern I worked on a motor controller which used > >PWM. A brushless DC motor ran on up to 120 to 170 volts at up to 10 to > >15 amps. A switching (PWM) power supply controlled the voltage applied > >to the motor. > > >An improved version used a microcontroller controlled digital PWM. I > >think the PWM frequency was about 20 KHz and the PWM had 5 bits of > >range. The same microcontroller monitored the motor position/speed to > >form a closed loop system. > > Was this motor designed specifically for this freq? When I first developed > this PWM motor controller, I was trying to run it at 20KHz also. But the > motor was down on power. Motor was an AstroFlight cobalt, 9.6V at 35Amps, > such as those used in R/C model aircraft. Going to the lower freq brought > the power back up. I looked at possibly skin effect, but the wire used in the > winds wasn't that large. > It could also be inductance on the windings was causing the power to be down more than predicted. I would think using a lower frequency would correct a problem in this area over using a high frequency. There may be enough windings that prevent the current from ramping up fast enough at 20khz. Roger ------------------------------ From: heinld theo Date: Thu, 04 Feb 1999 19:47:21 -0800 Subject: Re: DIY_EFI Digest V4 #85 Re: TC's and manual trans (was: Re: Smooth strategy) >>No way--a two element torque converter is a violation of Newton's laws!!>> >>Regards, Greg>> Greg I don't know much about Newton's laws however I have been under cars for the last 45 years, working mostly on auto trans. so I know a little bit about torque converters. To get torque multiplication in a 2 element TC you need curved vanes plus a different number of blades (vanes) in the turbine and impeller. There was usually a split guide ring (doughnut) as well. While this arrangement is not as effective as a TC with a stator it nevertheless multiplies torque and is therfore correctly termed a Torque converter. Theo from downunder ------------------------------ From: KD6JDJ@xxx.com Date: Thu, 4 Feb 1999 14:51:16 EST Subject: Re: fusible link questions Reply to Pat Ford I didnt intend to get into a long exchange of design criticism when I put my 2 cents in to this fusable link question answering post. On some (many) cars the wire that connects the alt. + to the battery+ is used as a shunt for the ammeter. When the ammeter must display both charge and discharge, the load that will be monitored for discharge must be connected to the alt. side of the shunt. So, the designers sometimes chose to put the link in that path. Sure there are ocassional problems as a result -- but they are few. I wanted to inform thoes of us that are rewiring an alternator + to battery+ that a fusable link is not needed. Also -- An alternator is not designed so that its diodes limit its output current. The stator does that. Yeah , I assume that ALL critical wires will be connected dirrectly to the battery , for the reason you state. For what it is worth -- Delco puts Avalanch diodes in their negative side of the bridge to 'suck up' thoes destructive transients. Jerry ------------------------------ From: Terry_Sare@xxx.com Date: Thu, 4 Feb 1999 14:36:29 -0600 Subject: RE: PulseWidthModulation comments >From another list for robots: PWM comments. Funny that it shows up on two different list at the same time. >>>>>>>>>>>>>>>>>>Inserted from srs list <<<<<<<<<<<<<<< Hi, The speed of the PWM for speed control of a DC motor is *highly* dependent on the motor you are controlling. For example, the little 3/8 inch diameter motor that I use require a PWM frequency of at least 20 KHz (which isn't doable with a standard HC11 setup). Luckily, most of us aren't pushing the performance envelop, so most of the typical motors used in mobile robots can be run with a wide range of frequencies. As far as the inductance, if you run the frequency up, the inductive field doesn't collapse as much, so the impedance isn't such a problem. Depending on the motor, there are bad ranges, however. Cheers, Bill Harrison http://www.sinerobotics.com Peter McCollum wrote: > 1000 ticks at 8 MHz would be 8 KHz, right? I'd say that that's much too > high. The inductance of a DC motor is probably high enough that the 8 Khz > signal is seeing a very high impedance. Thus, very poor power transfer. > > I would try 20,000 or 30,000 ticks instead - giving you 300-400 Hz. > That's the range I'm using on two projects so far, and it seems to work > OK. > > Pete M. > > On Sun, 31 Jan 1999 22:27:08 -0500 (EST) Derek Konigsberg > writes: > > > Anyways, does anyone know what period works best for maximum > >torque in PWM motor control? Right now, low speeds yield almost no > >torque > >and I can effortlessly stop the wheels with my hands. I'm using a > >period > >of 1000 clock ticks (8MHz clock) on a 68HC11E1. My high/low (duty > >cycle) > > ___________________________________________________________________ >>>>>>>>>>>>>>.end insert - -----Original Message----- From: rauscher@xxx.com] Sent: Thursday, February 04, 1999 1:21 PM To: DIY_EFI@xxx.edu Subject: Re: PulseWidthModulation comments Ludis wrote: >Years ago as a summer intern I worked on a motor controller which used >PWM. A brushless DC motor ran on up to 120 to 170 volts at up to 10 to >15 amps. A switching (PWM) power supply controlled the voltage applied >to the motor. >An improved version used a microcontroller controlled digital PWM. I >think the PWM frequency was about 20 KHz and the PWM had 5 bits of >range. The same microcontroller monitored the motor position/speed to >form a closed loop system. Was this motor designed specifically for this freq? When I first developed this PWM motor controller, I was trying to run it at 20KHz also. But the motor was down on power. Motor was an AstroFlight cobalt, 9.6V at 35Amps, such as those used in R/C model aircraft. Going to the lower freq brought the power back up. I looked at possibly skin effect, but the wire used in the winds wasn't that large. >Some comments applicable to fuel pump / coolant fan PWM control: > >The pulse width and frequency needs to be very stable, otherwise all the >inductors in the circuit will squeal like stuck pigs. The original >analog system screamed constantly. The digital system (running the same >switcher!) was totally silent as long as the pulse width wasn't >changing. Software in the microcontroller updated the pulse width every >millisecond. When the pulse width needed to be changed often, this >produced a 1 KHz tone from the electronics. The amount of noise was >directly proportional to the load on the motor. You could actually hear >the computer "straining" against a high load. Sounds as thou the noise is from the P/S, and not the motor. I've only heard a light whine from the motors, and only at lower speeds. So hopefully the noise won't be enough to drive folks out of the car . >The main switching transistor was a TO-220 package mounted on a dinky >little heat sink. You don't need a massive TO-3 transistor. In the >above system, cooling the rectifier diodes was actually more of a problem. Oh so true, in the writeup I showed that even at 15 Amps, the MOSFET only needed to dissipate a little more than 5 watts. Only a small heat sink required. The key to the proper MOSFET, is low voltage drop through it. This keeps losses down and heat also. >BTW, in one mode, this motor was reversed every several tenths of a >second. This applies to a thread from several weeks ago. My brain is fading here, possibly relative to a motor driven FPR? BobR. - -- ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Thu, 4 Feb 1999 14:17:03 -0700 Subject: Re: Intake Runner Length >-----Original Message----- >From: ECMnut@xxx.com> >To: diy_efi@xxx.edu> >Date: Thursday, February 04, 1999 1:27 PM >Subject: Re: Intake Runner Length > >Dog leg ports, ain't bad. >The best head on our tractor has a big dog leg in them. This is on a direct >injection engine (fuel shoot in cylinder), and it realllllyyyyyyyyy works. >There are soo many wife's tales, rumors,and lies about port shapes. > Yep--but diesels be different--it's a real trick to get the fuel to find all the air before it's too late anyhow. Giving up a little air going in for the swirl that helps the fuel find more of what does get there IS a BIG help. Regards, Greg ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Thu, 4 Feb 1999 14:31:35 -0700 Subject: Re: DIY_EFI Digest V4 #85 >Re: TC's and manual trans (was: Re: Smooth strategy) > > > > >>>No way--a two element torque converter is a violation of Newton's laws!!>> > >>>Regards, Greg>> > >Greg >I don't know much about Newton's laws however I have been under cars for >the last 45 years, working mostly on auto trans. so I know a little bit >about torque converters. To get torque multiplication in a 2 element TC >you need curved vanes plus a different number of blades (vanes) in the >turbine and impeller. There was usually a split guide ring (doughnut) as >well. While this arrangement is not as effective as a TC with a stator >it nevertheless multiplies torque and is therfore correctly termed a >Torque converter. > >Theo from downunder Let's don't mistake slip--lock-up speed characteristics for torque multiplication. If you have torque A coming into the unit on the input shaft, and torque B going out of it on the output shaft, For A to be different from B, there has GOT to be a torque reaction against the case. No way out of it. Otherwise we are talking about a close kin of the famous (?) 300mpg carburettor! The usual way for that torque reaction that MUST exist for a torque increase (multiplication) to exist, is for it to get transmitted into the case is from oil hitting the vanes on the (third) stator element (a third element), with that force going from thence through the sprag clutch into the case. Sure--you could just cast the diverter vanes into the case and do it, but then they could never freewheel at speed and let the thing act effectively like a two element fluid coupling at low slips/high speeds. No offense or flame here--this is just basic statics. Regards, Greg ------------------------------ End of DIY_EFI Digest V4 #89 **************************** 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".