BarendB Posted September 13, 2017 Report Share Posted September 13, 2017 Hi GuysTime for another question on my ECU install, the alternator in the 99+ MX5's have charging controlled by the ECU.Now I struggled to find information here about this for the MX5's, but did find some info on Haltech's forums on how they control the alternator charging.The base settings are listed below so people can follow this discussion without opening a base map:Frequency: 250HzStart Duty: 75%Minimum Duty 0%Max Duty 100%Gain 100Target Voltage 14.7Output InvertedPlease use a spare PWM output to the charge wire of the Alternator.Use a 470ohm pull up to 12v on the chosen PWM output.Please use the software settings previously mentioned.Remember to check to voltage at each RPM site before racing!I'm pretty sure this is not a problem to setup in Link, my question is more on the how I'll go about doing this, and what he means by "inverted output" and "470ohm pull up from 12v"Thanks in advance Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 14, 2017 Report Share Posted September 14, 2017 Those settings above look like they are intended for some type of basic closed loop system. We dont have such a function in our firmware.I suspect you might be able to get reasonable results using a GP PWM table with Bat V on one axis and Eng RPM on the other. The "inverted output" would be used to tell the output whether 100% in the table means "100% on" or "100% off" - you dont get the choice with a GP PWM table so you would just need to get your numbers the right way around. Our aux outputs have a 1.5Kohm pullup builtin to the ecu so I suspect you wont need that.You've seen these things right?: http://www.ebay.com/itm/222318261582 Quote Link to comment Share on other sites More sharing options...
BarendB Posted September 15, 2017 Author Report Share Posted September 15, 2017 Thanks I ordered one of those, the alternate option was to get another alternator from an earlier 97 Mx5 1800 or Mazda 626 but they're hard to come by.Thanks Adam Quote Link to comment Share on other sites More sharing options...
o_dd Posted September 22, 2019 Report Share Posted September 22, 2019 Hello The MX5 alternator is PWM controlled with reference to this thread. But the voltage is not stable Is there a map that can be helpful? Quote Link to comment Share on other sites More sharing options...
BarendB Posted September 22, 2019 Author Report Share Posted September 22, 2019 @o_dd Hey mate, I abandoned the idea of trying to control the Alternator with the ECU, just could not get it stable. I wen't through several trail and errors even bought an aftermarket control circuit that is suppose to control the charge etc... My advice, source an alternator from a 1800 NA, those have the controller built in. Finding them second hand is bit hard, I just ordered one from my local parts store. FYI I think this is what I bought... but as per the spec the regulator is built in.https://www.repco.co.nz/en/brands/oex/oex-alternator-12v-80a-mitsubishi-style-mxa234/p/A1192640 Quote Link to comment Share on other sites More sharing options...
o_dd Posted September 23, 2019 Report Share Posted September 23, 2019 14 hours ago, BarendB said: @o_dd Hey mate, I abandoned the idea of trying to control the Alternator with the ECU, just could not get it stable. I wen't through several trail and errors even bought an aftermarket control circuit that is suppose to control the charge etc... My advice, source an alternator from a 1800 NA, those have the controller built in. Finding them second hand is bit hard, I just ordered one from my local parts store. FYI I think this is what I bought... but as per the spec the regulator is built in.https://www.repco.co.nz/en/brands/oex/oex-alternator-12v-80a-mitsubishi-style-mxa234/p/A1192640 Thank you BarendB I wanted to control the alternator with Link. I look for the alternator who taught me Quote Link to comment Share on other sites More sharing options...
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