DIY_EFI Digest Wednesday, February 16 2000 Volume 05 : Number 064 In this issue: Re: Fuel pressure manifold reference -DIY_EFI Digest V5 #62 Emulator boards Re: Emulator boards RE: efi specifics Re: Holley TBI Injectors VS Pressure Diacom Related Software spark question: high current or high voltage Re: spark question: high current or high voltage Re: MC3334 based ignition Bosch Injector info 636 Bad Hotmail Re: Bad Hotmail Halogen H7 - non-efi -help from Europe Re: MC3334 based ignition RE: ECU6 board Re: Bosch Injector info 636 Mixture measurement using Lamda and EGT Re: Bad Hotmail RE: MC3334 based ignition See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Tue, 15 Feb 2000 11:29:02 -0500 From: "Clare Snyder" Subject: Re: Fuel pressure manifold reference -DIY_EFI Digest V5 #62 > > > -----Original Message----- > > From: owner-diy_efi@xxx.org]On > > Behalf Of Andy Wyatt > > Sent: 11 February 2000 06:47 > > To: diy_efi@xxx.org > > Subject: Fuel pressure reg/EGO Qs > Date: Fri, 11 Feb 2000 11:57:50 -0500 (EST) > From: Mary or Stephen Burgess > Subject: Re: Fuel pressure reg/EGO Qs > > At 05:47 PM 2/11/00 +1100, you wrote: > >Hey y'all > > > >Could someone please explain to me: > > > >1. Why do they have fuel pressure regulators manifold pressure referenced? > >Why don't they just take this into account in the fuel map? Is it so that > >the injectors are open longer at idle, improving trimmability and hence idle > >quality? > > In order for an injector to be properly calibrated you need to know the pressure drop across the nozzle - ie how much difference between rail and manifold. No simpler method than referencing the regulator to manifold instead of atmosphere. This means at high manifold vacuum the rail pressure drops so a given opening time produces the same flow as it would under load when manifold vacuum is low and rail pressure increased. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 13:43:57 -0500 From: David Cooley Subject: Emulator boards After the family crisis and the system crash I bailed out in SC, they sent me to Ft. Bragg to do an installation at Womack Army Hospital. Kept us there until the acceptance testing was out of the way and I got back Saturday night. Went thru the boards last night and noticed they all seem to have areas where the data/address lines are either missing copper or are covered solid in one or two places. Verified my drawings had .010 spacing and .010 minimum line width, PCB house spec'd at .008 minimum spacing and .008 line width. Spoke with them about 30 minutes ago and they stated they were having problems with some of their processing equipment... they said if I would have been willing to pay the $200.00 "UL testing fee" it would have caught the errors. Regardless, this is the 2nd time I've been hosed and they agreed to refund the cost. Everyone that has sent me a check please send me a note with an address so I can get the money returned. For a 100.00 item, this has been a ridiculous battle. Thanks, Dave =========================================================== David Cooley N5XMT Internet: N5XMT@xxx.net Packet: N5XMT@xxx. Member #7068 We are Borg... Prepare to be assimilated! =========================================================== - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 13:16:41 -0600 From: steve ravet Subject: Re: Emulator boards Dave -- what board house did you use? I'll put them on my "do not use" list. - --steve David Cooley wrote: > > After the family crisis and the system crash I bailed out in SC, they sent > me to Ft. Bragg to do an installation at Womack Army Hospital. Kept us > there until the acceptance testing was out of the way and I got back > Saturday night. Went thru the boards last night and noticed they all seem > to have areas where the data/address lines are either missing copper or are > covered solid in one or two places. Verified my drawings had .010 spacing > and .010 minimum line width, PCB house spec'd at .008 minimum spacing and > .008 line width. Spoke with them about 30 minutes ago and they stated they > were having problems with some of their processing equipment... they said > if I would have been willing to pay the $200.00 "UL testing fee" it would > have caught the errors. Regardless, this is the 2nd time I've been hosed > and they agreed to refund the cost. Everyone that has sent me a check > please send me a note with an address so I can get the money returned. > For a 100.00 item, this has been a ridiculous battle. > Thanks, > Dave > > =========================================================== > David Cooley N5XMT Internet: N5XMT@xxx.net > Packet: N5XMT@xxx. Member #7068 > We are Borg... Prepare to be assimilated! > =========================================================== > > ---------------------------------------------------------------------------- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 14:07:04 -0800 From: "Al Lipper" Subject: RE: efi specifics Todd, The MAP sensor can mount anywhere - it is connected by a vacuum hose. The TBI unit either needs a custom adapter plate if you use a junkyard TBI, or, what might be easier is to get a Holley TBI unit and a holley to GM adapter plate. The TPS is part of the TBI unit. Good luck. Al > -----Original Message----- > From: Todd Schinell [mailto:todd_schinell@xxx.com] > Sent: Monday, February 14, 2000 12:06 PM > To: efi@xxx.org > Subject: efi specifics > > > I have a bone stock 429 cadillac motor and I am > looking to inject it, mostly just for kicks and the > experience, but driveability and efficiency would be > wonderful side effects. > > From your web pages I gathered that mechanically I'd > need a throttle body first of all. Sensors: > O2,coolant temp, MAP, TPS. An electric fuel pump and > injectors. > I was looking for recommendations on where you got > your sensors and the best mounting spots. For the 02 > you said the remote heated type mounted aft from the > manifolds (I say aft because it's not a car, it's a > ship!) Obviously there is a stock coolant temp > fitting. But the tps map and throttle body are > question marks. I don't have much choice in manifolds > for the 429 (stock unit is the only type in existence) > so I guess I'd need either a rochester bolt pattern or > a converter of some type. Any clue what to look for > at the yard? > > As far as the real engineering, the electronics > associated as with your schematics, I have a EE friend > who is interested in helping me out with the ideas. > I'm not completely in the dark when it comes to > assembly and architecture either. Any help > appreciated! > > -Todd Schinell > Computer Science > Norwalk, CT > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 18:56:43 -0800 From: "Walter Sherwin" Subject: Re: Holley TBI Injectors VS Pressure > >Date: Mon, 14 Feb 2000 22:09:28 -0600 >From: "Shane Buss" >Subject: Re: Holley TBI Injectors VS Pressure > >What's the lowest effective pressure these injectors work well with? I >should have the 80#ers tommorrow.. > >Shane Shane, I think I covered this info in a previous DIY post directed your way, but in the event that the message did not get to you I will include a copy below. Technically, you can operate these injectors at pressures well below 12psig and still have "flow", but, the cone shape/spray pattern/atomization characteristics all become really messy and begin to really affect the overall performance! Not something you really want to do. Stay around 12-15psig. Good luck with your new injectors. Stay in touch if any more questions. Walt. _____________________________________________ The #85 injector that I mentioned below is in fact the same thing as what is oft referred to as the "#80" injector. In either case this is the injector which comes standard from Holley in the 900 CFM 4bbl TBI, injector P/N 250R-51A, service P/N 522-26. The #85 actually flows about 85 pounds per hour of fuel @ 15psig (Holley's rated pressure). It will slip into your smaller TBI injector housing pod. When four of these injectors are housed and fed via the pod passages, and driven via four 4/1 amp P&H drivers, you can usually get about 310 pounds per hour of maximum fuel flow. I would aim to calibrate your setup at a pressure somewhere between 12-15psig. Any less pressure, and the injector spray quality is really "globbery". 15-18psig will get you more volume, which in your case you don't need. Over 18psig, and you risk hydraulic shut down of the injectors. I don't know if you intend to purchase new or used injectors, but here's a tip that will save a lot of headaches when either buying used, or performing regular maintenance at a later date. Measure the resistance of each of the four injectors, from the very tip of one terminal post to the very tip of the other terminal post. The spec is 1.3 ohms +/1 0.1 ohms. Now measure the resistance of the same injector, from the cylindrical collar that appears to sheath the terminal post to the other collar around the other terminal post. The resistance should be identical to what you just measured above. If not, there is an electrical resistance and/or break between the collar and the terminal post somewhere. If you look at the mating connector, you will see that the connector terminals engage over the outsides of the collars, and that current must flow through the collars in order to enter the terminal posts and windings of the solenoid. I've been caught by this a couple of times myself. Sometimes a dab of solder at the collar/post interface will fix this problem. Sometimes not. _____________________________________________ - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 18:06:24 -0600 From: "Shane Buss" Subject: Diacom Related Software Hey is there any freeware software out there that works similar to diacom? I have Diacom, but its a really old version and was just curious if there's something better.. Anyone tried writing there own software? Doesn't look that hard.. Shane - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 19:12:08 -0600 From: "Brian Franchuk" Subject: spark question: high current or high voltage I'm currently working on a high current ignition system but I've got a couple questions. Is it better to use a wider gap and higher voltage or a small gap (lower voltage 10-15kV) and very high current (spark current in the 1-5 amp range)? There was some talk about plasma jet ignition a while back. Has anyone built such a system? Thanks. Brian Franchuk - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 21:08:04 -0500 From: Seth Subject: Re: spark question: high current or high voltage If you are spark igniting gasoline, then I don't have an opinion. But if it is propane or methane (CNG), then a shorter duration, higher voltage ( capacitive discharge) spark can fail to reliably light those two fuels. A conventional ignition actually works better for those two gases. - -Seth Brian Franchuk wrote: > > I'm currently working on a high current ignition system but I've got a > couple questions. Is it better to use a wider gap and higher voltage or a > small gap (lower voltage 10-15kV) and very high current (spark current in > the 1-5 amp range)? There was some talk about plasma jet ignition a while > back. Has anyone built such a system? > > Thanks. > > Brian Franchuk > > ---------------------------------------------------------------------------- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 21:26:08 -0500 From: rr Subject: Re: MC3334 based ignition The problem with a high-voltage MOSFET is the RDSon. The losses can be higher than expected. And they are expensive. Figure at 5-amps current and 0.4-ohm RDS, that's a 2-volt drop across the switch. A bipolar will be about 0.7-volts. BobR. Mihai Alexandru wrote: > diy_efi@xxx.edu > MC3334 based ignition > > Hello, > > I intend to build an ignition based on the MC3334 > chip. > I have searched the efi archives and found some nice > info about this, but I still have some uncleared > points that I hope someone might answer: > > 1. Did anyone use a power MOSFET instead of the > MJ10012 ? And if so, which were the changes in the > schematic from Motorola? I intend to use an IRFP450. > 2. How should I make the reluctor pickup? > > Thank you very much, > > Mihai > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > ---------------------------------------------------------------------------- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 22:03:35 -0500 From: Doug Mansfield Subject: Bosch Injector info 636 I searched the archives and came up empty handed. Does anyone have any info on this Bosch injector? 0 280 150 636 Thanks, Doug - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 19:29:40 PST From: "mike mager" Subject: Bad Hotmail Greetings! How can I get rid of that nasty "Hotmail" advertisement at the bottom; I have tried "-- " without success. Thanks, Mike - -- ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 21:44:41 -0600 From: "Shane Buss" Subject: Re: Bad Hotmail get a real email account.. hotmail makes its money by advertising.. you cant get rid of that - -----Original Message----- From: mike mager To: diy_efi@xxx.org> Date: Tuesday, February 15, 2000 9:40 PM Subject: Bad Hotmail >Greetings! > >How can I get rid of that nasty "Hotmail" advertisement at the bottom; I >have tried "-- " without success. > >Thanks, >Mike >-- > > >______________________________________________________ >Get Your Private, Free Email at http://www.hotmail.com > >--------------------------------------------------------------------------- - - >To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) >in the body of a message (not the subject) to majordomo@xxx.org > > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 21:55:41 -0600 From: Tom Sharpe Subject: Halogen H7 - non-efi -help from Europe I just picked up a German car with 2 pair of H7 headlight bulbs, 55 watt - - US Standard. What are the available H7 bulbs in Europe? Any high power or high wattage or blue tinted? What is the Euro standard? Thanks in advance. Tom PS I'm running 80/100s in both other cars with no complaints. New technology is great. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 23:09:59 -0500 From: Joeo Subject: Re: MC3334 based ignition Mihai Alexandru wrote: > > diy_efi@xxx.edu > MC3334 based ignition > > Hello, > > I intend to build an ignition based on the MC3334 > chip. > I have searched the efi archives and found some nice > info about this, but I still have some uncleared > points that I hope someone might answer: > > 1. Did anyone use a power MOSFET instead of the > MJ10012 ? And if so, which were the changes in the > schematic from Motorola? I intend to use an IRFP450. > 2. How should I make the reluctor pickup? > > Thank you very much, > > Mihai Hi, I tried to use that chip as well. I used the MJ10016 (if memory serves) Darlington. I had some problems with charge time and heat sinking. Those trans. can get VERY hot - make sure you use good heat sinks. I ended up not using the MC3334P and just used the ignitors from an RX-7. I'm still having some problems with my ignition (building a distributorless ignition for my 1991 MR2 Turbo). What is your project about? Thanks. joeo - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 20:52:27 -0800 From: "Al Lipper" Subject: RE: ECU6 board This is a multi-part message in MIME format. - ------=_NextPart_000_0004_01BF77F6.9196C2E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Daniel, I work for California Polytechnic State University. Apart from that, our EFI company is Injection Logic (www.injectionlogic.com) and focuses on selling custom EFI system designs. ECU6 and ECU7 are the result of the research from the products we market. I believe that cooperation is the greatest way to increase knowledge and promote development, so I have chosen to share most of the data on the systems we design. The proprietary information generally has to do with systems designed for a specific application. Even so, I try my best to use what I've learned from that work to help people with questions. I'm very glad to hear of your progress with ECU6. One caution, unless your vehicle's electrical system is VERY noise-free, you will probably need some filtering on the power supply input, or it may spontaneously reset (or report incorrect RPM, or fire the injectors when it shouldn't). Good luck! Al P.S. Thanks for the update. -----Original Message----- From: Daniel [mailto:duagu@xxx.com] Sent: Tuesday, February 15, 2000 6:27 PM To: Al Lipper Subject: Re: ECU6 board Hi Al Thanks anyway, by the way, which institution or company are you working at? its because I will be putting down your name in the acknowledgements and was wondering if you were currently with any university. And i attached a text file with the ecu6 program. i removed all the coolant temperature and idle air code because i want to test for functionality of the system first, so it is quite a bit shorter. i also put the starting pw and initial injector volume in the lookup table as it would be easier to adjust and i dont have to trouble you all the time. Feel free to amend the program if you think there is anything wrong. Thanks Daniel ----- Original Message ----- From: Al Lipper To: Daniel Sent: Tuesday, February 15, 2000 10:07 PM Subject: RE: ECU6 board Sorry, but you got the last ECU6 board. We may however have some ECU7 boards in a few months. Al -----Original Message----- From: Daniel [mailto:duagu@xxx.com] Sent: Monday, February 14, 2000 6:40 PM To: Al Lipper Subject: ECU6 board Hi Al, Could I ask if you have any more ECU6 boards, because I would like another one. However this time I think I do not need the 8051 chip as I found a supplier for them. Although stocks are limited, they still have a few lying around. This time, could I send the money by telegraphic transfer as it costs 8 pounds just to make a money order. I think its a bit cheaper for me this way. If you do have, could you provide me with your bank details so that i can transfer the money directly? and i forgot how much was the original board already, could you please remind me how much it is if you do have extra boards. Thank you very much Daniel - ------=_NextPart_000_0004_01BF77F6.9196C2E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Daniel,
    I work for California = Polytechnic=20 State University.  Apart from that, our EFI company is Injection = Logic (www.injectionlogic.com) and = focuses on=20 selling custom EFI system designs.  ECU6 and ECU7 are the result of = the=20 research from the products we market.  I believe that cooperation = is the=20 greatest way to increase knowledge and promote development, so I have = chosen to=20 share most of the data on the systems we design.  The proprietary=20 information generally has to do with systems designed for a specific=20 application.  Even so, I try my best to use what I've learned from = that=20 work to help people with questions.  I'm very glad to hear of your = progress=20 with ECU6.  One caution, unless your vehicle's electrical system is = VERY=20 noise-free, you will probably need some filtering on the power supply = input, or=20 it may spontaneously reset (or report incorrect RPM, or fire the = injectors when=20 it shouldn't).  Good luck!
 
 
       &nbs= p;       =20 Al
 
P.S.=20 Thanks for the update.
-----Original Message-----
From: Daniel=20 [mailto:duagu@xxx.com]
Sent: Tuesday, February 15, 2000 = 6:27=20 PM
To: Al Lipper
Subject: Re: ECU6=20 board

Hi Al
Thanks anyway, by the way, which = institution or=20 company are you working at? its because I will be putting down your = name in=20 the acknowledgements and was wondering if you were = currently with=20 any university.
And i attached a text file with the = ecu6 program.=20 i removed all the coolant temperature and idle air code because i = want to=20 test for functionality of the system first, so it is quite a bit = shorter. i=20 also put the starting pw and initial injector volume in the lookup = table as it=20 would be easier to adjust and i dont have to trouble you all the=20 time.
Feel free to amend the program if you = think there=20 is anything wrong.
Thanks
Daniel
----- Original Message -----
From:=20 Al = Lipper
To: Daniel
Sent: Tuesday, February 15, = 2000 10:07=20 PM
Subject: RE: ECU6 board

Sorry, but you got the last ECU6 = board.  We=20 may however have some ECU7 boards in a few = months.
 
 
       &nbs= p;   =20 Al
 
-----Original Message-----
From: Daniel []
Sen= t:=20 Monday, February 14, 2000 6:40 PM
To: Al=20 Lipper
Subject: ECU6 board

Hi Al,
Could I ask if you have any more = ECU6 boards,=20 because I would like another one.
However this time I think I do = not need the=20 8051 chip as I found a supplier for them. Although stocks are = limited,=20 they still have a few lying around.
This time, could I send the money = by=20 telegraphic transfer as it costs 8 pounds just to make a money = order. I=20 think its a bit cheaper for me this way.
If you do have, could you provide = me with=20 your bank details so that i can transfer the money = directly?
and i forgot how much was the = original board=20 already, could you please remind me how much it is if you do have = extra=20 boards.
Thank you very much
Daniel
- ------=_NextPart_000_0004_01BF77F6.9196C2E0-- - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Wed, 16 Feb 2000 00:18:23 EST From: ECMnut@xxx.com Subject: Re: Bosch Injector info 636 Chrysler 2.2 TBI.. Flow numbers not given in my doc. Mike V > > I searched the archives and came up empty handed. Does anyone have any > info on this Bosch injector? > > 0 280 150 636 > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 15 Feb 2000 20:03:17 +0000 From: Ade + Lamb Chop Subject: Mixture measurement using Lamda and EGT Hi All, This has sort of thing has been basically covered recently however. What is the principal behind it? I understand about Lamda sensors and how they are so nonlinear that not very far off of Lamda 1 is in the region of full rail. I also understand that the EGT goes up with a lean mixture and down with a rich mixture. Do you use the Lamda as an absolute reading the EGT reletive to lamda? If so then how much change in temperature change do you get for a given change in mixture? How accurate is this method of measurement? Thanx, Ade - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Wed, 16 Feb 2000 00:56:02 PST From: "mike mager" Subject: Re: Bad Hotmail Thanks, Shane > >How can I get rid of that nasty "Hotmail" advertisement at the bottom; I > >have tried "-- " without success. >get a real email account.. hotmail makes its money by advertising.. you >cant get rid of that I've got so many (stinking!) E-mail accounts that I just sort of 'standardized' on one, and I don't use the others at all. Now that Microsoft owns them, pure commercial, no doubt. Thanks, Mike ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Wed, 16 Feb 2000 10:18:21 -0000 From: "Rich M" Subject: RE: MC3334 based ignition Hi Guys, A normal bipolar would have Vce(sat) around 0.7V, but not a darlington! MJ10012 quotes Vce(sat)=2V at Ic=6A, Ib=0.6A and Vb=2.5V - that's 1.6Watts dissipation just for base drive! How about a IGBT? Look at Motorola MGP20N40CL - Vce=400V (internally clamped), Ic=20A cont. Vce(sat)=1.8V max.(at 10A) Gate drive is like a logic-level mosfet ie. guaranteed fully on at TTL logic high(min) level, gate current is statically negligible, but highish gate capacitance requires a reasonably stiff drive for high speed switching. The gate is zener clamped to avoid damage from voltage spikes. This device was designed for coil switching and all in a TO220 package style. www.mot-sps.com for details. Hope this helps. Rich > -----Original Message----- > From: owner-diy_efi@xxx.org]On > Behalf Of rr > Sent: 16 February 2000 02:26 > To: diy_efi@xxx.org > Subject: Re: MC3334 based ignition > > > > The problem with a high-voltage MOSFET is the RDSon. The > losses can be higher than expected. And they are expensive. > > Figure at 5-amps current and 0.4-ohm RDS, that's a 2-volt > drop across the switch. A bipolar will be about 0.7-volts. > > BobR. > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ End of DIY_EFI Digest V5 #64 **************************** 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".