DIYEFI.org Forum

I have heard a few complaints from MS users about the ruggedness of VB921 - so i searched for other alternatives and here are some of the datasheets i came across-

http://www.onsemi.com/pub_link/Collater ... 205N-D.PDF
http://www.onsemi.com/pub_link/Collater ... 204N-D.PDF
http://www.fairchildsemi.com/ds/FG/FGB3040CS.pdf
http://pdf1.alldatasheet.com/datasheet- ... asheet.pdf
http://www.datasheetpro.com/datasheets/ ... sheet.pdf/
http://pdf1.alldatasheet.net/datasheet- ... asheet.pdf
http://www.datasheetcatalog.org/datashe ... 40CL-D.PDF

Thanks for that :-)

I may have a few more options that I've collected in the hardware wishlist thread to add here too. It's good to put them all in the same place. I know FlappySocks has one that he uses with success, and so does Tony, but they may both be on your list already. The VB921 isn't even manufactured anymore anyway, so no worries with people using that ;-)

I personally prefer OEM ignitors. It's really hard to beat their physical packaging and robustness and they are electrically tolerant as well. I used J121 and equivalent units as have a few of my mates, but most of them are fairly good.

Fred.

Sorry i havent been around for a while i have been super busy with my bike stuff and testing out my board i made for the busa.

I am using the IRGB14C40LPBF-ND from digikey and so far they have been bullet proof for my setup both in COP and WS mode all the way to 10,800 RPM im sure there are others that will fit the bill but these seem fine to me.

I just installed the IGBT upgrade kit from RS-Autosport today, and it fixed the startup misfire problem I have had for the last two years.

Fairchild ISL9V5036P3

This is pin-compatible with the VB921.

I would recommend this for use in this project.

The Fairchild ISL9V5036P3 is a fine part. The only issue is, in the TO-220 package, it's an End-Of-Life (EOL) product that is on Lifetime Buy status.

EOL parts are a great way to get a super deal on large quantities.

Go to fairchildsemi.com and enter either 'ignition igbt' or 'ecospark' into the search box. The 4 parts that Fairchild lists are surface mount TO-263 / D2PAK parts. They are all good parts for EMS use. The surface mount package somehow makes some users balk.

I don't think a D2PAK is difficult for most diy users to attach. I mean, it isn't like it's an 0402 cap or something. (0.4 mm × 0.2 mm)

- Jim

I'm curious why do we seem to lean to the IGBT's vs power MOSFET's?

http://en.wikipedia.org/wiki/Power_MOSFET
http://en.wikipedia.org/wiki/IGBT

I'm more familiar with MOSFET's because they typically have the reverse diode, preventing a number of issues.

The clamping voltages are too low for ignition coil fly back in affordable units with suitable characteristics.

Fred.

Back in the late 90s i played around with IRF740/IRF730 and IRF510 for ignition coil based tesla experiments - they have a tendency to burn out too quick and they are courteous enough to pass the high voltage back into the control electronics when they fail - i have had some spectacular 555 IC blowouts and arcs. They are not too forgiving about running without load ... and they usually need a MOV to get any decent reliability.

But then again - it wasnt a typical automotive ignition setup......

In the case of the auto-protected ones they will probably just overheat and they will definitely disrupt the coil discharge pattern extending the spark duration and making it less "hot". I spent some time looking for FETs that would work and didn't find anything. That was a while ago though.

Fred.

Found some good stuff about IGBT's here. Sounds like a handful of folks here know quite a bit about IGBT's but they are fairly new to me. I'm reading the basic and basic 2. They include circuits with fly-back, that I think are perhaps the best I've seen so far.

http://www.fairchildsemi.com/apnotes/an_byfam_d9.html