I have now assembled the voltage regulator circuit, but would like to test it. I have access to adjustable power supply at school.
Do i just connect ground to power supplys negative and 12v to power supplys positive, start from 12v and go up to 14.4 where it should go to zero? 500mA should be enough?

Also, i downloaded the latest ms2extra 3.3.0 firmware onto unit, and followed by uploading the basemap but its showing all these erroes. Is is normal? my usb->serial adapter is working, tunerstudio was able to detect the firmware on my unit.
https://i.imgur.com/joGI56o.png
https://i.imgur.com/9piCys6.png

 

the field out should drop to under 5v (i always see around 3v) when the input power reaches 14.2v.

 

Right

 

Tested the voltage regulation circuit at school today, with mixed results.

https://i.imgur.com/BdHAehU.jpg
Here is my connection, i set it to 500mA and 12v DC. Couple times it cut the voltage on "field out" at ~15.2v but the multimeter didint give me a voltage.
Ones it cut at ~14.4v and after that it refused to cut the voltage. I went up to 17v without results.
I have double-triple checked everything, all components should be in right places and i dont have shorts.

My local eletronics store didint have PN2907A, insted i used 2N2905A transistors. Could this be the problem?

Here is a closer look to my circuit
https://i.imgur.com/wkJcTbw.jpg
https://i.imgur.com/6HEwn4T.jpg
Looks chaotic, but nothing is actually touching and shorting out.

12v and gnd was too hard to jump, so i modified the circuit a bit
https://i.imgur.com/9Uf6rr9.jpg

It should still work the same..?

 

Sorry if it feels like i'm bringing this thread back from the dead.

Where did ya'll get the components to build the alternator control circuit? Any website you have good luck with? I tried Radioshack (really the only place in town) but they didn't have a bunch of the parts.

Thanks

 

Eric,
I got mine from Fry's in Duluth... Wait, when did you move from L'ville to Florida?

Try an online parts supplier such as digikey or mouser. I would expect Radioshack to be a bust.

 

Well its been a few years now. And yeah Frys's would be my go to place if I were still is L'ville. Just ordered everything through digikey. I just hope I ordered everything correctly. There is a lot of **** on there.

 

Bought my components off a local store, but didint actually get the regulator to work. Ordered one off westfield, works great.
Alternator pcb | Frank's Westfield MX5 Alternator pcb |

 

I did find that in my searches. How did you end up mounting it?

 

Basically i just glued it on one of the rails in the top casing

https://i.imgur.com/OnWny6q.jpg

 

So I am I the process of trying to wire in all the parts for sequintal injection, but I can't find the schematic anywhete and the one in the post does not exist anymore at that link. Can any one help me out?

 

find the microcircuit module schematics and duplicate the inj outputs.

its a driver a 100k reisistor and a 1K resistor. that's it.

 

This is heresy but I just put a 97 or back alternator with a built in regulator made of much stouter stuff than whatever you can solder to that board. In over half a million miles of miata driving (wife, son and my miatas) never had a regulator go out yet. Bearings, well, not so good

New alternator too much? used ones are really el cheapo.

 

I buy all my components at digikey.com.

do you want the pn list of everything to buy?

 

 

FWIW, NB alternator has more power output if I'm not mistaken and also higher output voltage. Output voltage on the NA can be rather low, especidally on older units. Ideally you need 14.4V
Measure yours some time.

 

if you want more AMPs, which is the most important, buy the auto version of the the alternator. they all have 5 more AMPs IIRC.

something like that.

 

Thank you for posting this. I was able to follow the traces and map out the circuit using DIY's photo, but liked to see how it was laid out on the proto area. I know this is probably a super noob question, but the DIY sequential board has holes INJ3 and INJ4 to go right to the connector board, but I see that you wire yours into the 3 and 4 right there on the proto area. How do you get that back to the 4V and 4X on the connector board?

 

Those holes go back to the just above the INJ2 holes on the edge of the board near the connector board.

So I jump 4X and 4V from there.

 

Wow... How did I not see those. Must be the jumbled mess of jumpers. Thanks!