Alternator regulator design

[goboatingnow]

Following on from my comments elsewhere , I was hoping to design an open source low cost external alternator regulator.

( there is already an Ardunio open source but it’s the forerunner to the wakespeed and is rather over complex )

I intend to use either an NXP or Infineon dedicated regulator IC. These run at around $12 in one offs.

These provide basic PI ( proportional integral ) regulation and field coil current control with pwm. They incorporate startup procedures and engine load balancing to help prevent hunting , and can sense field coil currents , all in a simple 5 lead TO220 package

They have a LIN interface so are fully controllable

Hence adding a simple micro ( probably ATTINY series ) then could be added to effect specific controls needed for a boat

( as an alternative I was thinking of using an ESP32 which could be extended to add Bluetooth configuration )

What minimal features do we need for boat use

(A) programmable voltage set points and or LA charging profiles

(b) external current sensing ?

(C) alternator temp sensing ( the regulator ic can actually do that itself and could be bolted directly to the alternator , but probably best left as the ambient sensor )

(D) battery temp sensing ?

(E) people have mentioned the need to easily switch between current settings ( say a programmable high low switch )

Interesting Victron is opening up its Bluetooth advertising protocol using the GATT profile , this opens up battery temp , current and voltage sensing via Bluetooth.

I’m leaning towards Bluetooth even though it means writing an app to handle reporting and setup

I’d also like to try and make it compatible with the Victron infrastructure ( ie build in Ve.direct )

So is there consensus on what a simple regulator should be capable of

For me the biggest cost is setting up a bench based alternator to test this. I’m looking at acquiring a 1.5 HP motor and fabricating a test rig. ( scrap car alternator )

[goboatingnow]

Furthermore I’m conscious of other attempts that ended up with convoluted PC based setup processes etc. my own view is basic functions should be directly set-able using buttons etc. ( maybe a 2 line lcd and a few buttons etc )

I’ll work on the basic design during the autumn once my sailing season ends but hardware will have to wait till the winter 2023 Jan -March period as I need access to my “ lab”

[Rumrace]

Boy that’s interesting stuff. I’ve played with Arduino and raspberry but never considered them for that application.
Blue tooth sucks really. Have you considered wisa?
My audio video is Wisa which is a totally private

[goboatingnow]

Originally Posted by Rumrace

Boy that’s interesting stuff. I’ve played with Arduino and raspberry but never considered them for that application.
Blue tooth sucks really. Have you considered wisa?
My audio video is Wisa which is a totally private

The basic regulator function will be taken by a dedicated alternator regulator chip , probably Infineon , or ST L9918

These are controllable typically by a LIN interface ,

Hence really the attached micro is just doing some supervisory roles ( particularly temperature monitoring and definitely battery ( alt output ) current monitoring ) so it’s main function is to provide a user interface

I’m keen initially to develop a device that can be setup without any other equipment , hence the Idea of a 2 line lcd and a few buttons. This is better then say Balmar and way better then wakespeed.

The device has the usual alternator connectors , minimally B+, Field ( rotor ) , phase , GND , in addition a user programmable input line , remote off line ( for BMS use ) alarm line and “ idiot “ light line. I think some leds could show basic status ( bulk , absorption , float, and alarm ) rather like mppt and mains chargers show these. This is because unlike stock car regulators this regulator is optimised to charge batteries.

Of course stock alternators need to be modified to bring out a phase signal and the field connections. So this type of unit can’t just be “ dropped in “ to a stock system.

That’s the idea , other comms methods like Bluetooth etc. are really in the “ nice to have “ arena and typically never get finished anyways!!

One simple option is to emulate a Victron Ve.direct device serial output and hence piggy back onto that eco system.

Small volume component costs look to be around $ 40-50 inc PCB not including assembly. Considerably less in any volume.

[Rumrace]

So is the main purpose to protect the alternator.
Every night every city sends energy to earth. Toronto sends this energy to a pump station on Toronto Island down the End of Muggs Channel. The pumps fill huge air tanks which run dynamos on the shore line the public think are art pieces.
In boats we use zener diodes like motorcycles or turn our shinny dangly parts into corrosion magnets. How about excess energy put to good use. ?

[markxengineerin]

Among my many wacky projects, I am converting an old "Heart Interface" alternator regulator (sometimes available for about $25-$50 on ebay) to be controlled by an Arduino for the purpose of charging my lithium bank in a controllable way.

The Heart Interface should be adequate for this purpose by itself, as it has the usual voltage setpoints for "bulk/accept" and "float". The problem is, they aren't consistent in practice. The bulk knob (potentiometer) needs to be rotated clockwise at low RPM or higher bank voltage to get the same output amps, and the opposite. I'm not sure why. It gets old having to adjust all the time, and it can be dangerous to "forget".

My solution is to replace the manual potentiometer "bulk" knob with a digital potentiometer, MCP41X1, controlled by Arduino. The logic for turning it up or down is derived from a current sensor on alternator output, battery voltage, and a thermocouple bolted to the back of the alt housing.

It all works.... Just haven't had time to convert from breadboard to something I want on the boat.

Documentation will be done... someday.

I will be following this thread with interest, as I would like to eliminate the Heart Interface at some point. The logic for keeping it is that it handles a lot of EE stuff that I know I'm not qualified to bypass or re-design- much lower risk to limit my hacking to a single component, the potentiometer, and let the rest of the device function as normal.

[Rumrace]

If you need a water proof case I print one which may work. I print them in white ASA has chemical fuel UV and strength.
Takes 16 hours to print all the pieces then you need 3 orings. I made a solar panel holder to maintain the battery but the raspberry makes short work of the battery if it looses power. I even print the water tight wire nuts cause you can buy them in white.
I’m making one in dark blue right now.

[Rumrace]

Basically a jam jar with wire ports because I’m too cheap to buy a $45.00 waterproof box

[goboatingnow]

The heart interface is merely a form of regulator , this is the same as my idea of using a controllable regulator IC like the L9918 , these are completely self contained automotive regulator ICs in a TO220 package.

On its own that offers no as advantage over a stock alternator regulator. But these latest regulator ICs now have a control bus that lets an external micro ( or Ardunio ) reprogram the regulator , this is primarily a voltage setting interface.

Once we have a voltage controlled alternator we have the building block to build a regulator orientated towards charging batteries as opposed to car regulators that are primarily designed to act as a power supply.

[markxengineerin]

The heart interface is merely a form of regulator

Yes

Below are the things that were easier for me not to deal with, plus the risk of unknown unknowns, me not being an EE or having any experience at all in this area. There is a lot going on in the Heart Interface box, but I do hope it can be replaced by that tiny chip, that would be very elegant.

[Rumrace]

I have a little Onan. What’s it doing right the kicker can’t

[goboatingnow]

Originally Posted by markxengineerin

Yes

Below are the things that were easier for me not to deal with, plus the risk of unknown unknowns, me not being an EE or having any experience at all in this area. There is a lot going on in the Heart Interface box, but I do hope it can be replaced by that tiny chip, that would be very elegant.

Yes chips like that are the basis of all modern internal stock regulators. It’s a very simple control purpose hence the circuit is very straight forward.

The interesting bit is the Lin interface ( a one wire half duplex system ) this allows external controls to override the set voltage point.

Once we have that we have a configurable regulator which is all we need.

[Rumrace]

Oh I re read and answered my own question. Since the engine needs no spark put the alt to better use. Quit thinking like a car.

[goboatingnow]

Originally Posted by Rumrace

Oh I re read and answered my own question. Since the engine needs no spark put the alt to better use. Quit thinking like a car.

No idea what you mean , the alternator in a car plays no different part to a diesel. Both are car systems power supplies.

[Rumrace]

Yes i get that point. I have a power boat also but the alt has to run 3 hydraulic pumps a blower and 8 huge ignition coils. The two batteries don’t get much.
A diesel doesn’t waste juice on a spark