gpio with pnp for 4eat trans

[camomcharo]

In my prodject im using ms2extra to control 2.2 ecotec and gpio with meagashift 2110 to cantrol a 4eat trans the 4eat has bonded ground sols
I installed pnp tip 125s and p fet for some reason i thought the load sould be on the collector. I lost com with the board when I jumperd it, found 12v on
base. freaked then removed the jumpers reloaded 2110 got com back. Can annyone help with this wiring! do i need a npn like a ztx 450 in font of
the 220s? I looked at the flyback cirk with tip 125 and now im confused. if some one can help it would be much appreciated. (its a sand rail prodject)
rick.

[Bernard Fife]

camomcharo,

I am not clear what you are doing. Nor do I know anything about the 4eat. Are you following someone's instructions for your installation? Do you have a wiring diagram for your installation and/or trans?

The TIP125 datasheet is here: http://www.fairchildsemi.com/ds/TI/TIP125.pdf

There is an example of how to drive a TIP125 from a uP pin here: http://www.bristolwatch.com/ele/transistor_drivers.htm

Lance.

[camomcharo]

Lance,

Sorry for the lack of detail, I have a 4eat thats out of a subaru forister 03 the transaxle configuration works with
mid engine application, the problem is with the sol. coils there grounded in the case so i couldint use the GPIO
grounding cirkt (220 tip120). I used tip 125 pnp's and p-fet, soldering the base and colector as normal I bent
the emiter lead up and solderd the zener vert. and bent the lead at a 90`(band up)I soldered the leads in a ladder
form.With your help I learned that the pnp base needed to be grounded to it turn on. I soldered 7 ztx450s to a project
pc board, I removed the 220s base resistors and jumperd the trigger board there.I turned the board on and it works!
Im going to install it in the car and do some tests ill post back on the progress.

Lance, thanks very much for the help, Rick.

[frankster]

i have a 5 eat 05 subaru same issues ..
so you just changed the drivers to a positive 12v system ? are there any instructions on this ?

[camomcharo]

Frankster;
You will need to wright up your own procedure, but there is info and support to help you complete your project.
NPN's flow into the collector and out the emitter the prossesor sends 5v to the base grounding the circuit. The
PNP's flow into the emitter and out the collector and grounding the base activates the transistor. You must use
a smaller NPN to do this I used a ZTX 450 you can use a smaller transistor if you want. The circuits are linked
above and the values are in the post above. check the voltages on the header before you jumper! They must be
under 5v I'll att. a pic. My trans has 2 sol. for shift valve A&B and I didn't use 2/4 DC It dumps the clutch press.
and the 2 timing sol's buffer the accumulator's these are not supported in the software. I used the table and shift press.
to tame the shifts. I used ford voltage for sifter input, A sires of resistors with values to create voltage drops close to the default as possible. The last problem I had was with PE1 I connected it to GPI2 with debounce circuit this keeps it from floating
and connects it to the default table 1. Don't use the supported build instructions build each circuit you need and test.
I don't know how this compairs to the 5EAT but maybe it will help.If you need more help just ask.

[camomcharo]

Here's my board pic

[Subaru_EA82_4EAT_AWD]

Hi, nice job with the mod. board.
Sso You have the GPIO working on the Subaru 4EAT? The duty C setup (AWD transfer clutch) working correctly?
I am very interested in this...I am soon going to try and set it up on an Older version of the Subaru 4EAT in my XT coupe, but I assume it will be mostly the same...

Kind regards.

[camomcharo]

Subaru;

I did get the trans to work I had trouble with the ford voltage, adjusting the resister values fix the issue. My app is in a sand rail so I didn't need the AWD clutch I removed the clutch and machined a aluminum plate for the end of the trans. My trans is a 03 phase 2, 1999 and early i believe are different so the sol.s control differently. it's possible to control the AWD clutch but I would assume that the program would need to be modified.