Hi everyone, much love from Italy!
So as you have read in the title, i am trying to build a Car Headunit power circuit for a Raspberry PI 5 in this case.
I have implemented some protections (not sure if they are any good, since i am a novice in this…) and most of the parts are AEC-Q100/101.
As you can see in the schematics there are 2 separate circuits, one for power (the one on the top) and one for shorting the J2 pins on the Raspberry when the ACC line changes state, so that i can safely turn on and off the raspberry without ever cutting power.
Every part is documented online, except for the DC/DC converter (Tobsun EA50-5V).
I found some other solutions like the TI LM61480-Q1, but it would require me to create and print a PCB, which I am not sure i would be able to do myself…
If you guys have any suggestions I am open to them! I really want to learn something here, and also build a project that does not explode and destroy my BMW E30, while being extremely reliable for long term use.
Sorry we can’t provide too much advice on this.
Additionally, if your main concern is to prevent damage to your vehicle, you could use a 12V battery or a DC power supply to power the system for testing. Connect a voltage and current meter to monitor the voltage and current for each connection to ensure they are within safe limits. Once you’ve confirmed everything is fine, you can try connecting it to your car, which should help avoid basic errors. Also, remember to use a fuse or similar protection for safety.
ok no problem mate!
yeah well that’s nice advice. i will be trying that.
but what i am trying to achieve with this circuit is cleaning the power signal since in automotive environment it tends to be very loosely 12V, oscillate quite a lot during startup, depending on temperature etc, changing during long runs…
I wanted to also know if the EMI filter for the power line was necessary and adequate…
do you have any other forum suggestions to ask these kinds of questions? i’m kinda lost
