Project - Car aux heating with glow plugs

Hi and 1st of all sorry for the bad english.

I whant to make a board that uses a arduino mini to use it like an aux car engine heating.

The board must do this:

For the board to start heating the engine it must have 3 conditions: 1. The car voltage must be at minimum13.8v 2. the engine temp must be below 30 degree C 3. when te 1st and 2nd conditions are made, the board waits 10 seconds to start the comand of heating.

The heating comand will activat a High amp relay that will heat am the glow plugs in the engine cooling system.

The board will olso have 3 LED, one for each condition is its made.

Can you help me make this project, i know that i need a digital temp meter and a high amp relay but in rest i dont know how to measure the voltage and how to make the code. Someone made a borad like this... here Thanks

csl89: Hi and 1st of all sorry for the bad english.

The heating comand will activat a High amp relay that will heat am the glow plugs in the engine cooling system.

Why do you want glow plugs in the cooling system ?

They are normally used in the ignition system. Do yo mean block heaters ? Although at 30 deg i do not see why .

this systems are in the VW passat 200-2005 diesel engines end controled by the car ECU. The glow plugs are drifrent from the ones that start the engine but same principle. The stay in a houseing in back of the engine and in the cold winter it helps the engine heat up faster. And i whant to put one of this system on a mitsubishi pajaro.

this is from the passat

|333x500

http://i866.photobucket.com/albums/ab224/vicius_the_one/www_passatb5_ro/DIY%20Instalare%20CGP%20pe%20Passat%20B55%20cu%20PTC%20OEM/cgp1.jpg

and i use this one from a Ford |500x375 http://www.clubopel.com:8080/uploads/2013-01/47447_wc38uhnly.jpg

csl89: this systems are in the VW passat 200-2005 diesel engines end controled by the car ECU. The glow plugs are drifrent from the ones that start the engine but same principle. The stay in a houseing in back of the engine and in the cold winter it helps the engine heat up faster. And i whant to put one of this system on a mitsubishi pajaro.

I know too little about car electronics to be helpful i thinh.

This seems to be more of a mechanical or automotive problem, although i suspect an arduino could do the electronics for you if the mechanics are correct.

The components are "heaters" not "glow plugs",they will not glow while immersed in water. Please use the correct terminology.

How many Amps do they draw?

What you want is fairly basic to program. A voltage divider for volts, temperature sensor and a MOSFET to drive the relay.

Weedpharma

weedpharma: The components are "heaters" not "glow plugs",they will not glow while immersed in water. Please use the correct terminology.

How many Amps do they draw?

What you want is fairly basic to program. A voltage divider for volts, temperature sensor and a MOSFET to drive the relay.

Weedpharma

Sorry, dont know how to say corectly in english.

I whant to use: - 1 arduino mini - 1 digital temp. Meter - 1 mosfet with 12v output for the arduino and relay. - 1 voltage devider - 3 leds - resistors The arduino will check the conditions and then activate the relay. Do i need something more?

Draw up the schematic diagram, then get some practice with the basics of using an Arduino, and next have a go at writing the code. If you strike problems, you can always ask here for help, but you must try first. No one is going to design your circuit and write your code for you, unless you're extremely lucky, or you offer to pay them.

I whant to make it alone, but i asked because maybe you got better ideas from mine, so i know what to buy... When i know exactly what to use ill make a schematic.

csl89: I whant to make it alone, but i asked because maybe you got better ideas from mine, so i know what to buy... When i know exactly what to use ill make a schematic.

The main ingredient appears to be the temperature-sensing element. You don't need a digital temp meter, they're for humans to read, not Arduinos. You could start by researching this aspect of the project. Do you want it inside the cooling system, or attached to the outside somewhere?

Please also let us know the current requirement for each heater.

Weedpharma

weedpharma: Please also let us know the current requirement for each heater.

Weedpharma

On the passat the fuse for all 3 plugs is 60A so i guess 20A per plug maximum. I think ill use a car plugs relay (about 80-85 A) and activate it by a tranzistor with the arduino

This type of relay will probably have a relatively high coil current so it would probably be better to use a logic level MOSFET to switch the relat.

Weedpharma

I made a quik schematic. What do you think?

csl89: I made a quik schematic. What do you think?

I think your Arduino will burn up, if you supply 12V to it's 5V input as shown.

Also, as mentioned by weedpharma, you'll probably need to use a MOSFET to switch the relay. An 80A relay will draw too much coil current for a single bi-polar transistor.

The rest looks OK. Actually, a quick glance at the temp sensor datasheet indicates that it needs a pullup resistor on the data pin. You should check into that by reading the datasheet thoroughly. I don't have time right now.

My mistake i ment lm7805 not 12... my mind was with that because i recently used it. I made this quiq at work.. didnt have all the data sheets. Ill change with a mosfet the transistor, put a resistor at the temp sensor and see if ill need something more.

With the voltage devider shoul i calculate for 15v? So i get exatly 5v? Then ill need to use R1 2k and R2 1k

csl89: My mistake i ment lm7805 not 12... my mind was with that because i recently used it. I made this quiq at work.. didnt have all the data sheets. Ill change with a mosfet the transistor, put a resistor at the temp sensor and see if ill need something more.

With the voltage devider shoul i calculate for 15v? So i get exatly 5v? Then ill need to use R1 2k and R2 1k

I think that allowing for 15V is a good idea. A car charge system is typically 14.2 to 14.4V, so 15V gives a margin of safety.

Otherwise, with those small changes, it's looking good at this stage. My only extra suggestion is that you add capacitors liberally, across the supply pins of the Arduino and the temperature sensor, and also a reservoir capacitor on the input of the '7805' would be a good idea. Maybe a 100uF electrolytic or even larger. (I suspected that you'd accidentally written 7812 instead of 7805, too. ;) )

Ok thanks. Tonight ill do the schematic with the updates in eagle and post the new one to verify

Today i made some more modifications:

  1. Added a npn to start the arduino when te car key is on. (So the sistem wont start if you put the battery on external charging)
  2. Changed the relay npn with a N chanel mosfet.
  3. Changed the temp sensor wires (found a tutorial with this method)
  4. Added a 100uf C for the LM7805.
  5. Added a flywheel diod to the relay
    What do you think?

You still have LM7815.

You will also get more than 5v due to the voltage drop across the Tr.

I would use a logic level MOSFET. These turn on at a lot lower voltage that what yours will.

Weedpharma