Car Power Supplys BOOST AND EGT

Hi everyone, just a few questions that I would like some help with. Im going to use an Arduino Uno in my diesel car to monitor boost levels and the exhaust temps (EGT). I have all the components that I think i need to get the project started except for a power supply. I see that the Arduino could take the 12V from the cars battery but my concern is how dirty it is and spikes from the alternator etc.

I have found this power supply: DC-DC Power Module 25W (DFRobot DFR0205) | Little Bird Australia

Specs:
Input voltage range:3.6V-25V
Output adjustable range:3.3V-25V
Constant output current:5A@5V
Max Output Power:25W
Switching Frequency:350KHZ

I will be running the Arduino Uno, a 2x16 LCD with Serial backpack, thermocouple amplifier and a boost sensor and a few LEDS. Would this be fine? Any suggestions?

Also because its a diesel and it needs to have the accessories on for approx 4 seconds (for the glow plugs) what would be the best approach to have the Arduino stay on between glowing the plugs and actually starting the car...if that makes sense haha.

Thanks in advance and I look forward to hearing some opinions.

Cheers Mitch.

I think you need only 500mA.
With a capacitor (I guess 2200uF ... 4700uF), you should be able to keep the Arduino running during starting the car.

I can't tell if the DC-DC converter can handle spikes. Perhaps the Arduino can handle spikes better than that DC-DC converter.
Can you find a DC-DC converter that has an input up to 60V or so ?
Perhaps it is better not to use a DC-DC converter, and build a protection circuit.

A car is a noisy environment. The spikes on the 12V could be above 100V.
The Arduino is for prototyping and has very little protection.

The inputs should be protected (for example with protection resistor and clamp diodes). Even if it is only the sensor. The wires of the sensor could pick up nasty spikes.

The 12V should be filtered with a low pass induction and capacitor circuit.
With a diode, and a capacitor, and a simple voltage regulator like the LM317.
The LM317 can have up to 40V between input and output voltage.

Erdin:
I think you need only 500mA.
With a capacitor (I guess 2200uF ... 4700uF), you should be able to keep the Arduino running during starting the car.

I can't tell if the DC-DC converter can handle spikes. Perhaps the Arduino can handle spikes better than that DC-DC converter.
Can you find a DC-DC converter that has an input up to 60V or so ?
Perhaps it is better not to use a DC-DC converter, and build a protection circuit.

A car is a noisy environment. The spikes on the 12V could be above 100V.
The Arduino is for prototyping and has very little protection.

The inputs should be protected (for example with protection resistor and clamp diodes). Even if it is only the sensor. The wires of the sensor could pick up nasty spikes.

The 12V should be filtered with a low pass induction and capacitor circuit.
With a diode, and a capacitor, and a simple voltage regulator like the LM317.
The LM317 can have up to 40V between input and output voltage.

Thank you for the reply. I'm not sure what the spikes would be on the vehicle, perhaps I will take some measurements and see what it goes up to.

You say that It would be better to use a protection circuit, do you have any links you could show me to get me started? Or what I can search for? I'm fairly new to all this so any help is much appreciated because I don't want to fry any of the components.

I see I can use the LM317 (like you suggested) to provide a constant current, but what about the rest of the circuit?

Thanks alot, Mitch

The LM317 is a voltage regulator, which can also be used as a constant current.

I ment using the LM317 as a voltage regulator, instead of the DC-DC converter. Just as an extra protection.
You could also use a 7808 or 7809 as a voltage regulator, as mentioned in this thread, http://forum.arduino.cc/index.php/topic,13345.0.html

I can't find a schematic for a 12V car protection circuit right now.

beastrado:
Hi everyone, just a few questions that I would like some help with. Im going to use an Arduino Uno in my diesel car to monitor boost levels and the exhaust temps (EGT). I have all the components that I think i need to get the project started except for a power supply. I see that the Arduino could take the 12V from the cars battery but my concern is how dirty it is and spikes from the alternator etc.

I have found this power supply: DC-DC Power Module 25W (DFRobot DFR0205) | Little Bird Australia

Specs:
Input voltage range:3.6V-25V
Output adjustable range:3.3V-25V
Constant output current:5A@5V
Max Output Power:25W
Switching Frequency:350KHZ

I will be running the Arduino Uno, a 2x16 LCD with Serial backpack, thermocouple amplifier and a boost sensor and a few LEDS. Would this be fine? Any suggestions?

Also because its a diesel and it needs to have the accessories on for approx 4 seconds (for the glow plugs) what would be the best approach to have the Arduino stay on between glowing the plugs and actually starting the car...if that makes sense haha.

Thanks in advance and I look forward to hearing some opinions.

Cheers Mitch.

You need a special automotive power supply that is designed to suppress the spikes and surges you will see in a car. You can get specially designed modules such as this one

This has basically the whole circuit required to provide stable power.

Usually in the case of a glow plug WTS you do not lose power so a regulator such as this should continue to power your Android (it does in my Chevy Surburban)

Craig

craigcurtin:
You need a special automotive power supply that is designed to suppress the spikes and surges you will see in a car. You can get specially designed modules such as this one

5pc DC-DC Buck Converter Step Down Module LM2596 Power Supply Output 1.23V-30V | eBay

This has basically the whole circuit required to provide stable power.

Usually in the case of a glow plug WTS you do not lose power so a regulator such as this should continue to power your Android (it does in my Chevy Surburban)

Craig

Hi Craig, after looking into it more, a few people have said the Buck Converter is the way to go... Although I would probably need one with a higher input because it might spike above 40V (ill try and get some measurements from my vehicle to see). I've thought of running it directly from the battery seeing as this will give me the cleanest supply, but then I will need to run a relay to have it turn off with the car so I think I will run it from an accessory switched line. Do you think this would be ok?

Cheers Mitch