phil@amdcad.UUCP (Phil Ngai) (12/31/84)
Many years ago I eliminated the points on my car with an electronic
ignition and have had trouble free service from that part of the
system ever since.
Yesterday my car wouldn't start and it took me an hour to figure
out that dew had shorted out my distributor.
It would be quite easy to get rid of the distributor with four
ignition coils and a little electronics which could not fail
in the way I experienced yesterday. It would also eliminate
the need to check and change the rotor.
The problem of course is expense. Existing ignition coils are
expensive. But so was computing power. Semiconductors have
changed the way modern engines are controlled. Semiconductors
can change the way engines obtain spark. Part of the reason for the
cost of ignition coils is the need to step up from 12v to 12,000v.
But with modern electronics and power transistors it would be
easy to drive a coil with 1,000v. Then the ignition coil would
only need to step up by a factor of 12.
Anyway, I hope an automotive engineer (if beer makers are on the
net, why isn't GM, Ford, or Chrysler?) will read this and think
about it.
Maybe I should talk to our product planning people about such an IC...
--
AMD assumes no responsibility for anything I may say here.
Phil Ngai (408) 749-5790
UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil
ARPA: amdcad!phil@decwrl.ARPAchris@amdcad.UUCP (Chris Moore) (01/03/85)
> It would be quite easy to get rid of the distributor with four > ignition coils and a little electronics which could not fail > in the way I experienced yesterday. It would also eliminate > the need to check and change the rotor. > > The problem of course is expense. Existing ignition coils are > expensive. But so was computing power. Semiconductors have > changed the way modern engines are controlled. Semiconductors > can change the way engines obtain spark. Part of the reason for the > cost of ignition coils is the need to step up from 12v to 12,000v. > But with modern electronics and power transistors it would be > easy to drive a coil with 1,000v. Then the ignition coil would > only need to step up by a factor of 12. > > Anyway, I hope an automotive engineer (if beer makers are on the > net, why isn't GM, Ford, or Chrysler?) will read this and think > about it. > > > Maybe I should talk to our product planning people about such an IC... > Phil - I've been working on that, but keep having problems with the silicon vaporizing when hit with 12,000 V. Chris Moore, AMD Product Planning
kitten@pertec.UUCP (karen hettinger) (01/03/85)
> Many years ago I eliminated the points on my car with an electronic > ignition and have had trouble free service from that part of the > system ever since. > > Yesterday my car wouldn't start and it took me an hour to figure > out that dew had shorted out my distributor. > > It would be quite easy to get rid of the distributor with four > ignition coils and a little electronics which could not fail > in the way I experienced yesterday. > > But with modern electronics and power transistors it would be > easy to drive a coil with 1,000v. Then the ignition coil would > only need to step up by a factor of 12. > > Anyway, I hope an automotive engineer (if beer makers are on the > net, why isn't GM, Ford, or Chrysler?) will read this and think > about it. > > Phil Ngai (408) 749-5790 Unfortunately, I don't have my AUTOMOTIVE NEWS handy (it's packed away) but GM, more specifically Buick, if I recall correctly, will have an 85 (or 86???) model with *no ignition module*. If I could find the dang thing, I'd give you the specifics. Unfortunately, this news has been out for a while, so I can't recall the details. Anybody out there hear about it? -- kitten~ {ucbvax!unisoft | scgvaxd | trwrb | felix}!pertec!kitten
lee@cosivax.UUCP (01/04/85)
I believe that Buick has eliminated the distributor on one of their new engines. The coil is basically three coils, with output from a individual coil going to two cylinders, the off cylinder also firing during its exhaust stroke. Timing is accomplished from magnetic switches on the flywheel.
doug@terak.UUCP (Doug Pardee) (01/04/85)
> ... GM, more specifically Buick, if I recall correctly, will have an > 85 (or 86???) model with *no ignition module*. Gee, I thought they ALREADY made diesels... :-) Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!doug
dss00@amdahl.UUCP (Deepak S. Sabnis) (01/04/85)
> > easy to drive a coil with 1,000v. Then the ignition coil would > > only need to step up by a factor of 12. > > And how is the 12 V supply from the battery to be stepped up to a 1000 V (without costing more than the reduction in cost of the ignition coil, if any). I hope you are not proposing that battery voltages of 1000 V be made standard. As a matter of fact my impression (from my earlier profession) is that the cost of all electromagnetic devices like coils and transformers have less to do with turns ratio and more to do with the (Volt*Ampere) product. The comments above are only to add to the factual accuracy of what Phil said; his original idea that distributors are a weak link and should be avoidable has merit and worthy of consideration by the auto engineers. While on the subject of improvements in autos, how about starting a discussion on electrical automobiles (including the hybrid variety which has a gas engine and an electrical motor to get best of the two worlds). -- Deepak S. Sabnis ...!{ihnp4,hplabs,amd,nsc}!amdahl!dss00 (408) 746-6058 (Opinions expressed above are strictly my own :-| )
steph@nsc.UUCP (Steph Rutel) (01/05/85)
Reply-To: steph@nsc.UUCP (Steph Rutel) Followup-To: Distribution: net Organization: National Semiconductor, Sunnyvale Keywords: In article <280@pertec.UUCP> kitten@pertec.UUCP (karen hettinger) writes: >> Many years ago I eliminated the points on my car with an electronic >> ignition and have had trouble free service from that part of the >> system ever since. >> >> Yesterday my car wouldn't start and it took me an hour to figure >> out that dew had shorted out my distributor. >> >> It would be quite easy to get rid of the distributor with four >> ignition coils and a little electronics which could not fail >> in the way I experienced yesterday. >> >> But with modern electronics and power transistors it would be >> easy to drive a coil with 1,000v. Then the ignition coil would >> only need to step up by a factor of 12. >> >> Anyway, I hope an automotive engineer (if beer makers are on the >> net, why isn't GM, Ford, or Chrysler?) will read this and think >> about it. >> >> Phil Ngai (408) 749-5790 > >Unfortunately, I don't have my AUTOMOTIVE NEWS handy (it's packed away) >but GM, more specifically Buick, if I recall correctly, will have an >85 (or 86???) model with *no ignition module*. If I could find the >dang thing, I'd give you the specifics. Unfortunately, this news has >been out for a while, so I can't recall the details. Anybody out there >hear about it? >-- > kitten~ > {ucbvax!unisoft | scgvaxd | trwrb | felix}!pertec!kitten I also seem to remember a few years back (I don't remember how many) of an article in a magazine (Motor Trend, maybe ?) that described an electronic ignition (sans distributor) that used logic, coils, and diodes (for directing the spark to the right cylinder). It seemed ingenious in concept, and I believe that Ford was planning to put it into production in one of their 4-cylinder models. (Now that I think about it, the magazine might have been Radio Electronics or the always defunct Popular Electronics) Does anyone remember this ? Is this trivia or am I dreaming ?? -- THE Steph'R @ National .....QUESTION : Where is the good life ??? ANSWER :___________ (Hint : Have you checked your attitude lately !!
gvcormack@watdaisy.UUCP (Gordon V. Cormack) (01/06/85)
A number of fallacies have been perpetrated in the discussion of electronic ignition. I wish to address some of these. First, an ordinary ignition coil has a step-up ratio of only 80:1, not 1000:1 as suggested. In fact, when the breaker points open, a potential of about 400 volts occurs across them and hence across the primary circuit of the ignition coil. Most electronic ignition systems operate with a nearly identical coil, but apply a 400 volt power supply directly to the primary of the coil, rather than depending on the inductance of the broken circuit. Supplying the 400 volt supply does, of course, require another step up transformer . This transformer is (relatively) low-voltage and low-power (It is of similar complexity to that found in the 6V battery replacement that drives your Walkman radio). Furthermore, this 400 volt supply can be shared among the ignition circuits for all the cylinders. It is infeasible to switch the 32kv output from the coil using semiconductor electronics. I can buy conventional coils for <$10 each at my local Canadian Tire store, so I don't see how the manufacturing cost could be much more than a couple of dollars. For a production system, the manufacture of four (or six) -plexes of coils would be of comparable complexity to the manufacture of the distributor. I would like to defend the conventional distributor a bit. First, it is a simple and reliable device. I have NEVER had to replace a distributor cap (except one I smashed in an accident), nor have I had to replace a rotor. Shorting is caused either by poor sealing in the original manufacture or by some nerd removing the cap (which is not necessary with a breakerless ignition). Second, the distributor provides dynamic timing adjustment as well as switching the high-voltage ignition pulses. A centrifugal mechanism advances the timing at high engine speed. A vacuum advance retards the timing under heavy acceleration or when the engine is about to stall. In order to replace these devices, one has add transducers and a considerable amount of logic to the ignition system. In conclusion, I think that totally electronic ignition systems will eventually take over from mechanical. However, the complexity of the system is increased, albeit encapsulated in some multi-hundred dollar "control module". That control module will require no adjustment during its lifetime. But when it fails, don't expect to be able to dry it off with a rag, or to file it down a bit, or do anything else other than to call a tow truck and wait while your local garage orders a new one.
mikey@trsvax.UUCP (01/07/85)
> I believe that Buick has eliminated the distributor on one of their > new engines. The coil is basically three coils, with output from a > individual coil going to two cylinders, the off cylinder also firing > during its exhaust stroke. Timing is accomplished from magnetic > switches on the flywheel. Sounds like what Honda has been doing for years. The high voltage lead is not grounded in the coil at all, the current path is spark plug to coil to the other spark plug. I've also heard that the scavanging spark helps emissions slightly. A very big side benefit is that by using separate coils, the effective dwell, and consequently the amplitude of the spark, is increased. My motorcycle can run through a furious cloudburst and not sputter, although I do. mikey at trsvax 55, it's not even a good idea, it S*CKS!
phil@amdcad.UUCP (Phil Ngai) (01/08/85)
> I would like to defend the conventional distributor a bit. First, > it is a simple and reliable device. I have NEVER had to replace > a distributor cap (except one I smashed in an accident), nor have > I had to replace a rotor. Shorting is caused either by poor sealing > in the original manufacture or by some nerd removing the cap (which > is not necessary with a breakerless ignition). Distributors do not last forever. When I pulled my cap to dry it off, I noticed the contacts were quite pitted, and my manual says to replace it when noticable pitting is present. When you think about it, spark erosion is inherent in the design. This applies to the rotor too. You are supposed to pull the cap and inspect it for wear periodically. > Second, the distributor provides dynamic timing adjustment as well > as switching the high-voltage ignition pulses. A centrifugal > mechanism advances the timing at high engine speed. A vacuum advance > retards the timing under heavy acceleration or when the engine is > about to stall. In order to replace these devices, one has add > transducers and a considerable amount of logic to the ignition system. I seem to recall some controversy about mechanical vs vacuum advance. As far as I'm concerned, they are both ugly kludges. Semiconductors are cheap. We have a saying, "all ICs will cost $5, unless they are plastic, which are less". The transducers can't be a big deal either. The presence of modern fuel injection means the necessary transducers are already there and designs without fuel injection (but why?) can take advantage of the high production volume of transducers to get low costs. > In conclusion, I think that totally electronic ignition systems will > eventually take over from mechanical. However, the complexity of the > system is increased, albeit encapsulated in some multi-hundred > dollar "control module". That control module will require no > adjustment during its lifetime. But when it fails, don't expect > to be able to dry it off with a rag, or to file it down a bit, or > do anything else other than to call a tow truck and wait while your > local garage orders a new one. Yeah, my timing belt broke and I had to call a tow truck. So that experience is not unique. I claim that an electronic distributor will not fail as often as the mechanical kind and is a step forward. In the last paragraph I explained why I do not expect the electronics to add much to the cost of the product. I guess I shouldn't mention another pipe dream of mine: electronically controlled intake and exhaust valves... You want a new camshaft profile, get out your computer terminal... -- AMD assumes no responsibility for anything I may say here. Phil Ngai (408) 749-5790 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil ARPA: amdcad!phil@decwrl.ARPA
burd@unm-cvax.UUCP (01/21/85)
> I seem to recall some controversy about mechanical vs vacuum advance. > As far as I'm concerned, they are both ugly kludges. > Semiconductors are cheap. We have a saying, "all ICs will cost $5, > unless they are plastic, which are less". The transducers can't be > a big deal either. The presence of modern fuel injection means the > necessary transducers are already there and designs without fuel > injection (but why?) can take advantage of the high production > volume of transducers to get low costs. > > > In conclusion, I think that totally electronic ignition systems will > > eventually take over from mechanical. However, the complexity of the > > system is increased, albeit encapsulated in some multi-hundred > > dollar "control module". That control module will require no > > adjustment during its lifetime. But when it fails, don't expect > > to be able to dry it off with a rag, or to file it down a bit, or > > do anything else other than to call a tow truck and wait while your > > local garage orders a new one. > > Yeah, my timing belt broke and I had to call a tow truck. So that > experience is not unique. I claim that an electronic distributor will > not fail as often as the mechanical kind and is a step forward. > In the last paragraph I explained why I do not expect the electronics > to add much to the cost of the product. > > I guess I shouldn't mention another pipe dream of mine: electronically > controlled intake and exhaust valves... You want a new camshaft > profile, get out your computer terminal... > -- > AMD assumes no responsibility for anything I may say here. > > Phil Ngai (408) 749-5790 > UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil > ARPA: amdcad!phil@decwrl.ARPA Here's one more vote for the conventional distributor and its mechanical "kluges". I've owned five cars in the 100K-140K mileage range and have never had a distributor problem. The inconvenience of filing or replacing rotor/cap contacts every 10,000 miles or so is far more preferable than the chance (agreeably small) of being left stranded. Those who believe in the magic and infallibility of electronically controlled engine components need only read this net on a regular basis for a sampling of reality. This is not a flame against progress, just a plea for sane and realistic of same. Smiling, as I pass you by, on my way to the bank. Stephen D. Burd Anderson School of Management University of New Mexico