I want an Arduino to read out the oil temperature of my car and display it on a small OLED. The biggest problem I've come across is powering the Arduino, since I do not have much experience with that...
My plan is using an MP1584 module (like this) to get 5V from the 12V Ignition line.
Things to consider: Voltage spikes of up to 120V when starting the engine and "power suck-out" surges from various loads like headlights etc.
As far as I understood, I should at least add two capacitors (for the input and output of the MP1584). Which ones to take though? I really have no idea, which capacity to choose and what else might be important.
Will there be a problem with the voltage spikes / power surges or can the MP1584 handle them?
the mp1584 should work fine for this. You may add some protection diodes and a fuse to your circuit.
I think you may need more than to capacitors, but you can have a look at this:
steamyy:
My plan is using an MP1584 module (like this) to get 5V from the 12V Ignition line.
Things to consider: Voltage spikes of up to 120V when starting the engine and "power suck-out" surges from various loads like headlights etc.
As far as I understood, I should at least add two capacitors (for the input and output of the MP1584). Which ones to take though? I really have no idea, which capacity to choose and what else might be important.
Will there be a problem with the voltage spikes / power surges or can the MP1584 handle them?
Thanks!
steamyy
The module you posted has built in capacitors. If you want more capacitance you can add more to the inputs and outputs. I would use electrolytic 100uF for the input and 470uF for the output.
Snubbing voltage spikes is another story. Chances are the caps and most of the components will not tolerate 120V. You should do some research about suppressors, they build these things for automotive. You can use metal oxide varistors and TVS devices to handle transients... 3Dgeo is correct about using a USB based charger.. I've never heard of anyone's phones blowing up from using one. Why not use a USB type source? Those plugs are designed with switching power supplies built into them.
Learning about building power supply is cool but can get complicated. Simple solution is should be fine.
I'm reluctant to using a chopped up usb charger, because they take up a lot more space, even with FFC cables. They are also quite a bit more expensive and I'd like to learn more about electronics/power supplies. The easiest solution would be to just buy a finished product from Zada Tech...
Would a TVS-diode like the 1N6280A-E3/54 be suitable?
As far as I understood, this is what the circuit would look like, right? (see attached)
Wouldn't that cause a short circuit when the TVS-diode "opens" at clamping voltage?
steamyy:
I'm reluctant to using a chopped up usb charger, because they take up a lot more space, even with FFC cables. They are also quite a bit more expensive and I'd like to learn more about electronics/power supplies.
More expensive? You're kidding!
steamyy:
Would a TVS-diode like the 1N6280A-E3/54 be suitable?
Reasonable, or one with an 18V working rating.
steamyy:
Wouldn't that cause a short circuit when the TVS-diode "opens" at clamping voltage?
That is exactly how it works to protect your equipment.
Notice the fuse? If the transient lasts long enough, or your MOV fails and shorts out, the fuse blows.
