Alternator Control box for standalone MS install for NB - Page 5 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 07-21-2009, 04:47 AM   #81
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

FYI I installed an RX-7 FD alternator and dealt with everything once and for all. As an added bonus, its a 100A alt compared to the 80A of the stock 99-05 Miata or the 65A 90-97.

Jim
Reverant is offline   Reply With Quote
Old 08-05-2009, 12:39 AM   #82
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

So I've got my little printed boards working, and the cars run and all that, but the alternator section doesn't seem to work at all.

Issues:
1)The battery light doesn't come on when the battery is low. In fact, it JUST starts to glow as I hit 14.0V, but dim, and gets slowly brighter.

2)Q8 gets hot - like ~60-65* C external, the ZTX690 I have there. It's a small little thing, maybe too little for the job. But that doesn't mean the light should behave differently.

3)The alternator control line never gets any real voltage on it (~0.025 volts or something....), and there's no current to ground or anywhere else useful.

4)I blew a fuse. This might not be related, and it took a long time to do it, running for 20 minutes (though only the last few at full voltage - I finally ran the car off the Mopar part).


Anyone got ANY ideas where I should start?

AbeFM : photos : Schematics and Issues schematics.
AbeFM is offline   Reply With Quote
Old 08-05-2009, 01:24 AM   #83
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

Here's another idea. Did I get my pin assignments wrong?



I wonder how it matches up with


R16,18 -> 3.3k
R17 -> 33k
Otherwise all values check out. And I think that's ok, you get the same ratios.

and

Last edited by AbeFM; 08-05-2009 at 04:04 AM.
AbeFM is offline   Reply With Quote
Old 08-05-2009, 02:01 AM   #84
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

Answer: Yes. I used a generic footprint, and I should have checked it first. Turns out I had the pin assignments wrong on the TL431. I'll check the rest and edit this post to reflect it.

That seemed the only chip with any real issues - replaced them with new, rotated parts... and still nothing works.

edit: Note to self - swap anode/cathode. Also, sleep before I do anything else, the second time I tripped just walking to the garage should have been a sign. At least this is all making a self-consistent story. :-)

Last edited by AbeFM; 08-05-2009 at 04:17 AM.
AbeFM is offline   Reply With Quote
Old 08-05-2009, 11:14 PM   #85
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

go figure, I put all the parts in how they are supposed to go, and it works. Neat.

Also, touching on what I saw posted earlier, as I connect the alternator (and go from 11.5 to 14.6 volts) RPM jumps about 200, every time and reversibly.

Thanks Jason!!
AbeFM is offline   Reply With Quote
Old 08-06-2009, 01:55 PM   #86
Newb
iTrader: (1)
 
Join Date: Jun 2006
Location: UK
Posts: 40
Total Cats: 0
Default

Is the 1k resistor you guys are using to limit the current to the 12v field coil circuit really necessary?
I ask because the adaptronic apparently now has a voltage sensing ability meaning I could potentially wire an output directly to the field coil...
giff is offline   Reply With Quote
Old 08-06-2009, 04:46 PM   #87
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

Even if not, put a 1k in the wire. :-)
AbeFM is offline   Reply With Quote
Old 10-30-2009, 07:04 PM   #88
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default Jason, your PM's are full!

A bunch of people are using this circuit now, and it seems to work flawlessly. The complaint I keep getting is the light doesn't shut off all the day. Is there a way to make the light more digital?
AbeFM is offline   Reply With Quote
Old 04-06-2010, 05:43 AM   #89
Senior Member
 
Join Date: Nov 2007
Location: Belgium
Posts: 939
Total Cats: 59
Default

Just for the sake of completeness:

Quote:
Originally Posted by JasonC SBB
Try connecting a small 0.1uF or 0.22 uF capacitor between the top and middle terminals of the TL431.
I tried this and it works.
WestfieldMX5 is offline   Reply With Quote
Old 04-06-2010, 11:18 AM   #90
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Quote:
Originally Posted by giff View Post
Is the 1k resistor you guys are using to limit the current to the 12v field coil circuit really necessary?
I ask because the adaptronic apparently now has a voltage sensing ability meaning I could potentially wire an output directly to the field coil...
The 1k resistor protects the output of the circuit from accidental shorts by the installer.

It *may* also be necessary for the alternator - I don't rememeber, it's been so long.

Re: controlling it from the adaptronic. It is unlikely that the Adaptronic aux output will have a fast enough sampling/looping/polling to properly control the alternator. That was the problem with the Hydra which was what I originally designed this circuit for. This circuit is designed to do it at 200-300 Hz IIRC.

If you insist on trying to make the Adap do it, do a PWM 2D table with duty cycle that goes from 100% at 14.1V to 0% at 14.5V.
JasonC SBB is offline   Reply With Quote
Old 04-06-2010, 11:26 AM   #91
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Can a mod edit this original post and say "a 0.1uF or 0.22 uF cap between top and middle terminals of TL431 is necessary to make the warning light act digitally"?

https://www.miataturbo.net/showpost....6&postcount=44
JasonC SBB is offline   Reply With Quote
Old 04-06-2010, 01:01 PM   #92
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

By your command.

Joe Perez is online now   Reply With Quote
Old 04-06-2010, 04:41 PM   #93
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

Quote:
Originally Posted by f_devocht View Post
Just for the sake of completeness:



I tried this and it works.
Heh, that only took like 6 months. Glad to hear it works. More and more I'm getting to hate my set up, but I don't want to rebuild my MS to work with this board. :-)
AbeFM is offline   Reply With Quote
Old 11-18-2010, 11:48 AM   #94
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 406
Default

7 month necro!

Is there a specific voltage I'm looking for on the field coil control output? I'm not EE-smart enough to determine what the magic circuit puts out. If I had to guess, it'd be 12V across a 1k.

I'm looking at having the megasquirt directly control the alternator with a generic output and some hysteresis. loop speed should be sufficiently fast except in extreme cases of high rpm and lots of processing going on--where it drops down to 125Hz or something.
y8s is offline   Reply With Quote
Old 11-18-2010, 02:17 PM   #95
Senior Member
 
Join Date: Nov 2007
Location: Belgium
Posts: 939
Total Cats: 59
Default

I don't think it's looking for a voltage but rather for a current. The closer the output gets to 14.4V, the lower the current it sends through the field wire.
WestfieldMX5 is offline   Reply With Quote
Old 11-18-2010, 04:42 PM   #96
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 406
Default

well if I send 12V out through a 1k resistor... V/R = 12mA

And when the voltage reaches the setpoint + hysteresis, V becomes 0 and V/R also becomes 0.
y8s is offline   Reply With Quote
Old 03-11-2011, 01:02 AM   #97
Junior Member
 
Golferluke's Avatar
 
Join Date: Oct 2009
Location: Springfield, MO
Posts: 497
Total Cats: 3
Default

Ok bringing this thread back from the depths. I installed the control box in the first post but its not working for me. At first I thought it was something I did wrong but after some testing today I'm pretty sure I've got it all hooked up right. The blue wire is getting 12v from the fuse box, case is grounded and the green wire is connected to the grey/red wire. Ok so I did some testing, with the stock wiring the ecu sends around 1v to the alternator through the grey/red wire and the system charges. While the car is running the green wire puts out almost exactly the same, slightly more maybe. But if I cut the grey/red wire the voltage on the green wire output drops to .58 volts. Stays at .58 when I connect it to the grey/red on the alternator and doesn't charge. If I disconnect the green and touch the grey/red wires back together the idle stumbles but recovers and returns to 1v and charging. Any ideas?

EDIT:
Oh forgot one thing, while the grey/red wire is cut, the dangling wire on the ecu side is putting out like 12v.
Golferluke is offline   Reply With Quote
Old 06-29-2011, 04:09 PM   #98
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

Matt:
****, I've been gone so long, I don't remember how many T's you get. I remember reading the voltage out of that thing, and yeah, it was very low. I think I posted it, but it was ~0.6-1.5V or something like that.

Luke,
Cutting the wire and seeing 12V is not odd - it's the car trying to get current to flow through something which isn't taking it.

As far as ideas.... I wonder if cutting the other wire helps? I know, since I was confused on mine, I ended up cutting lots of wires. :-) And some people have this issue, some don't. Wire "1-T" of the alternator. I know several people have had problems, perhaps it's worth doing - that and telling grey-red-striped from grey-red-dotted.
AbeFM is offline   Reply With Quote
Old 07-14-2011, 12:55 PM   #99
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 406
Default

Oh hai.

So I have run into what may be an issue with the alternator control circuit: SERIOUS BELT SQUEAL.

At startup.

I suspect the circuit is saying "Scotty, Gimme that power!" since voltage drops and the circuit engages the alternator thus increasing the load seen by the belt/engine during cranking.

So I want to add a transitor inside the megasquirt to address this.

will switching the ground of the circuit through a TIP120 cause problems? Would I be better off switching out the output wire or something else?

I have a TIP120 already wired in the megasquirt that switches to ground and I was just going to use that.

Thanks nerdy bros.
y8s is offline   Reply With Quote
Old 07-14-2011, 01:00 PM   #100
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

i dont see any reason the circuit ground couldn't flow through the TIP120. Heck i suggested a pn2222 last night.


but im also no EE.
Braineack is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 AM
Another Alternator thread ihiryu General Miata Chat 9 09-28-2015 11:22 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:05 PM.