ok, I take it back, my bad

OK, fair enough MM. But for the record, the inverter circuit for each of the coils should look like this. BTW, how do you make an image visible in the message, rather than as an attached image file?

Attach images as JPGs and then insert the resultant link (right click on the "attached file" link) into your post as an image.

Like so:

https://www.rx8club.com/attachment.p...1&d=1181254220

So, why does my circuit work?

While I have you, what would the best way be to make a simple circuit that pulls a 12v input to ground when given a 12v trigger (like a relay)?

MM:
My best guess as to why your circuit works is:
(-1) X (-1) = +1, or in words:
incorrect wiring of incorrect schematic= correct operation
The circuit would work correctly if you reversed the collector and emitter leads (I incorrectly said base and collector in an earlier post).

I'm not quite sure what you mean by 'pulling a 12v input to ground when given a 12v trigger' since both are normally considered inputs. If you wish, I'll try to be of help in any specific applications you have in mind.

As an example of activating a relay, you could use the inverter circuit where R2 represents the relay resistance. For equal drive and power supply voltages, the value of R1 would be R2(B/F) where B is the transistor Beta (current amplification) and F is some factor to ensure the transistor is driven into saturation (typically 2-5).

Example: Say your relay resistance is 120 ohms, and the power supply and drive voltages are 12 volts. B is usually at least 100 (see what is probably the world's most common transistor http://en.wikipedia.org/wiki/2N2222). Take F as 2. Then R1 would be 6000 ohms. Use something close and conventional like 6.2K (not too important since there is already a factor of 2 slop in the design and Beta is usually higher than 100).

A point to note if you are using relays is that a high voltage will be developed across the collector of the transistor when the current is interrupted. Unless the transistor is capable of withstanding this voltage, the usual way of eliminating it is to place a reverse biased diode across the relay. This is a common arrangement but it may also be possible to eliminate both the resistor and the diode in a 'follower' type of design.

Still can't post the image directly. When I right click on the link, what option to I select? I don't see anything that allows me to past as an image after selecting something. I use Firefox, but I also tried IE. Why did the image in this post appear as a thumbnail while in the previous post it appeared as a file (the first image was bmp, the second jpg)?

after you link it right click on the image name and then click on Copy Shortcut

you can then paste that shortcut into the Insert Image icon button command box

https://www.rx8club.com/attachment.p...9&d=1181572897

Just wanted to ask if anyone can post an ignition wiring diagram that identifies each of the three wires that go to each coil's connector. I need to know which one is the signal wire and what the other two represent. Thanks in advance.

Chris

basically PCM trigger, ground, and power supply

https://www.rx8club.com/showpost.php...&postcount=157

Are you saying that the first wire in the plug when looked from above is the signal wire? I am a little confused because the diagram you linked appears to have the signal wire in the middle(although I am by no means an expert electronics guy). I will be installing our ignition upgrade today and I'd much rather be certain than having to test it out with a multimeter. Thanks for the help.

Chris

The HKS has a plug and play harness. I need to know in what order the wires are positioned in the stock OEM plug.

Chris

Would a coil like this work? Or can you not do the Jacob's ignition upgrade like on the 3rd gens?

http://img241.imageshack.us/img241/1853/coilge2.jpg

Quick question ....http://cgi.ebay.com/ebaymotors/SILIC...Q5fAccessories

Those wires are ok ?

Yes they will work with the stock ignition system.

Question guys. I just intall my new sparks and cables. But the problem is i my check engine light is on.... should i wait? It will turn off ? THX !!! :)

holy thread ressurection!

was the light on BEFORE you changed the plugs / wires? Did you alter the coils?
you should find a way to get the code read so you can see what is causing it.
local auto parts stores can pull the code from you. (ie; Autozone)

Bump

They are NPN transistors. Base to collector would flow reverse biased.


Edit: Oops, didn't check the dates on the thread lol only 3 years late but hope it helped.

In consideration for the BHR ignition system, is this still a worthwhile mod?

Try checking the date of the first post.

Al resurrected this thread for us and a little history lesson.

Figured as much; I saw the mentioning of the HKS unit replacement, and recall reading elsewhere stating it was of no use w/ the BHR system.

You mean like the whit spot on the bottom of the coil... which means nothing.

Precisely.
We all believed it at one point.

Then, I started dissecting coils and experimenting and verified that the white spot is just mineral deposits collected by the magnetic field from the coil.

We also learned that the AEM was shit and the better route was the LS2.

Because I did the legwork.

See how that works?

MazdaManiac... The official Sherpa of the Rx8club

I much prefer this over the "Pied Piper" version...

Jeff did you ever test the coils that mazport used? I know its often a point that the weak point of that system was the ignition box but what about the coils themselves? Just curious.