Fan Speed Controller

So here is my first prototype for the speed controller.
Its very simple.

For this prototype I used a Sparkfun Pro Micro knock off: https://www.ebay.de/itm/133046307998
an ESC: https://www.ebay.de/itm/352680431363
a random Potentiometer
a bunch of wires

I use a 12.6 Volt Li-Po Battery on the desktop instead of the car battery

Luckyly i had a second rad with fan to salvage the cables and connectors from.
In the video you can see it in action: with the potentiometer i control the fan speed. Then I heatup the tempswitch with the heat blower that then triggers full speed fan till its cool enough again and goes back to manual speed control by potentiometer.



The ESC will only get power if the Ignition is on. The microcontroller is powered from the ESC's internal regulator. So everything is off if the ignition is off and can not draw any power.
I can add detailed description/tutorial if anyone is interested in rebuilding.
The esc will be mounted to the top of the radiator. Cables from ESC and tempswitch will go through a drilled  hole right next to it to the Microcontroller with attached potentiometer on the dash and I will add an indicator RGB-LED.


I can put it back to original (for MOT) in 1 minute by just popping in the old unmodified Y-cable.

Well done, pup up the details, could be interesting. Let us know how it goes.

Is this something that is a problem for tuv? Why?

I kept an eye out for you yesterday, but my van was the only Hijet there. Saw a Subaru E10 and a Suzuki Carry (both red) though. You didn't overheat on the way over or anything I hope!

Dear Lex! I am sorry I didnt make it out on Sunday. We sorta maxed it out on Saturday already. Anniversary bash with all the bells and whistles leaving me absolutely devestated on Sunday... The Hijets fine though so no worries. Your cars got some attention?

Now about the fan controller: Its fantastic to play around with the pot.
After ignition is on the controller waits 5 seconds before the fan starts so you can start the motor without the additional current draw of the fan. You can also set it to the off-position in winter anyways. Still I have to smooth it out a little since there is a deadzone at the end of the pot. But i think its a simple software solution.

I dont think TÜV will care or notice but if so there might be some regulation against it. So its good to be abled to rebuild it with just a new cable set within minutes.

PS.: Ill upload source code and build infos later.

Its now ready for the final soldering and install:
eliminated deadzones

added LED

It flashes every second during inital start up green LED
solid Green LED comes on in manual mode
Red LED in full mode
No LED in halt mode

The little button simulates the temp switch.

Code:


#include <Servo.h>

Servo myservo;
int potpin = A0; // potentiometer analog 2 digital input pin
int esc = 10; // esc signal output pin
int tmpsw = 5; // temp switch connection pin
int led1 = 4; // pot control mode indicator LED pin
int led2 = 7; // full override mode indicator LED pin

int val = 90; // init value of fan 90 = stop

void setup() {
  //Serial.begin(9600); //debug
  myservo.attach(esc); //instance of servo object
  myservo.write(val); //init ESC
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(tmpsw, INPUT_PULLUP); // input for temp switch (LOW when hot)
  digitalWrite(led1, HIGH);
  digitalWrite(led2, LOW);
  delay(200); // wait some milliseconds for car to be started and flash LED
  digitalWrite(led1, LOW);
  delay(800);
  digitalWrite(led1, HIGH);
  delay(200);
  digitalWrite(led1, LOW);
  delay(800);
  digitalWrite(led1, HIGH);
  delay(200);
  digitalWrite(led1, LOW);
  delay(800);
  digitalWrite(led1, HIGH);
  delay(200);
  digitalWrite(led1, LOW);
  delay(800);
  digitalWrite(led1, HIGH);
  delay(200);
  digitalWrite(led1, LOW);
  delay(800);
}

void loop() {
  if (digitalRead(tmpsw) == LOW) { // radiator is hot
    digitalWrite(led2, HIGH);
    digitalWrite(led1, LOW);
    val = 180;
  } else { // radiator is cold
    val = analogRead(potpin);            // read the value of the potentiometer (value between 0 and 1023)
    val = map(val, 0, 1023, 90, 125);     // scale it to use it with the 320 A ESC and the hijet FAN (125 will already give you full speed fan)
    if (val == 90) {
      digitalWrite(led2, LOW);
      digitalWrite(led1, LOW);
    } else {
      digitalWrite(led2, LOW);
      digitalWrite(led1, HIGH);
      if (val < 100) {//if the value is set too low for propper fan operation manually set to lowest working value (100)
        val = 100;
      }

    }
  }
  myservo.write(val);                  // sets the ESC throttle according to the scaled value
  //Serial.println(analogRead(potpin)); //debug
  //Serial.println(val); //debug
  delay(333);                          // waits and drink some tea (tree times a second is enough)
}



Are you in between jobs? You are taking old cars to a different level. The world needs more of this. If I only had space on my desk...

Done! Ready to go!



Thanks LEX this stuff gets me hyped.  Its gonna be great. The ESC is not even getting a bit warm. The squeeking sound from the Motor sucks a bit but i havent figured out a way to eliminate it. Its the PWM frequency. I dont think its easy to reprogramm the ESC as there is no manual to it.
I hope when installed it will be neglectable.

That's a loud beep... Might even be louder than the engine...

That would be cool. People might think its an electrical hijet



I will try some capacitors near the motor later. The fan can run at pretty low RPM and could run almost silently if that beeping wasnt there.

Tried a capacitor. Didnt work too well. Magic smoke escaped.

Did you take a deep breath?

Would this be of any help? https://arduino.stackexchange.com/questions/4610/how-to-eliminate-noise-from-pwm-controlled-12v-fan-at-low-speed

Yeah I could make it silent version if i was using only a transistor like they do in the exaple you posted. But in my case i use an ESC that has everything pre programmed.  I thought why reinvent the wheel if there are properly engineered ESCsfor the job that almost install plug and play. But it turns out I need another shot at it.

I will experiment with it. Its not really loud so maybe it wont bother me. its easy to install and it would be easy to change it from esc to transistor version. all the cables stay in position


I have to build a braket now so i can mount it upside down on the rad so it cant collect water.... l8ers

beautifull old oscilloscope i found in the thrash. Its hooked to motor. We can see the PWM from the ESC. Also look at the dirt from the fan as it acts as a generator when i stop input. Also occasional arcing of the motor can be seen.

I have installed it tonight. You cant hear the beeping while the motor is running. At least not in the cockpit. Have not checked from outside. There will be picture updates tomorrow.

I already love the starting beep sequence from the ESC when you turn on ignition.

https://imgur.com/a/fhaJr0u




BTW my blower doesnt work aon stage 1... any known bugs to fix there?

It's usually the very fragile Coiled Resistor on the Heater Body held on with 3 screws COOL JET. I will dig a heater body out for you to look at and the resistor and where it is placed. But not tonight. I haven't eaten since a bowl of porridge at 7-30 am after my 4.2 miles walk starting out at 5-20am and getting back home at 6-55am.
I'm STARVIN MARVIN.!!!

Thats  not much ... you are granted a second bowl of porridge then. Three bolts and a resistor sounds doable. Looking forward to your info. Thanks and bon appetito. I have not eaten today, too but i slept till midday. Then i laquored the backyard ramp and now im down for stranger things 3 finale and a bowlognese.... bit of sillyness to end the day

PS.:

Partnumber: 8713887701000




https://www.originparts.de/index.php?cl=search&searchparam=8713887701000


€ 31.-  daihatsu standart low price

.....i will fix the old one. if you have not already... dont dig it out i can handle it. but thank you very much for the support its really apreciated.

Fan controller status report: full satifactory

I am running the code i have postet above.
Its the easiest solution but it still takes some good soldering skills and basic arduino programming.
I used silicon wire, because its much softer and therefore doesnt break so easy at the soldering points. Also its heat resistant up to 200° C.
For the thin wire 28 awg for the thick ones 21 awg should be good.

As you probably know from our valued buyers guide by Highly Jetted: a fan switch indicates problems with the cooling system. So this mod might actually lower the value of your vehicle
In my case though i dont care because i am not going to sell.

Its absolutely not essential if you have a perfectly tight and proper cooling system.
For me its a precaution to keep the jet chill on hot days with lots of stop and go in the city.
Its the only way to stay calm and have the heat blower off on a sunny day as my soul has suffered several scatches from the past two head gasket failiures.

If you have any questions feel free to ask.

This is an awesome project.

I often thought about putting 2 temp sensors onto the hijet, one before the radiator, and one after the radiator.

Because when they normally overheat the radiator is stone cold because they are air locked.

By monitoring the before/after temp of the radiator, you can check how much heat the radiator is displacing.

How about you swap the fan switch for a proper temp sensor, then you could change the fan speed depending on temperature?

Thanks alot for you suggestions HJ!!!!!!

Would be great to have a temp read out at the rad indeed.
If the temps would differ too much from the motor sensor you could flash a warning light etc.

Also of course one before one behind the rad would be nice for calculating efficency corresponding to ambient temprature and speed and thereby anticipate auto fanning

And finally a coolant pressure sensor would be usefull to calculate for broken radcaps and early leaks.


If I ever warm this project up again ill start with the temp sensor to replace the temp switch.
For now its just doing its job and i have too many things going on.
But i will takle this again some day.