Automotive design consideration

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#1
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Hi there,
does everyone have ever design some kind of automotive related electronic stuff?

I'm going to make a kind of media player to fit inside my car. I've heard from people that car could generate a lot of noises and EMI's that would degrade the electronic circuit's performance (or maybe functionality). What should I do consider especially on designing power supply circuit? Casing? PCB routing&plating?

Thanks.

KISS - Keep It Simple Stupid!

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Vehicles are a tough environment.

Putting thermal, (very cold to very hot), humidity, and vibration aside for the moment...

Vehicle power supplies are very noisy. There are the usual voltage sags, car idling, headlights and seat heaters on..., and higher voltages, alternator charging the battery.

The interesting part is the high voltage spikes, of BOTH polarities, that are on the line. Google Load Dump, and variations on it. There are some actual specifications for automotive noise, which I've come across on a search or two, but don't have a ready reference to.

Note, also, that in the US most vehicles have a 12 V negative ground system. There are + ground systems in existance. Also there is talk of going to a 24 V standard, which gives significantly more cranking power in the same sized starter motor.

Recall, too, that many tow trucks routinely use 24 V to jump start a "dead" car.

Filter the heck out of your power supply, and protect it from Both polarity voltage spikes.

It doesn't sound like you will be interfacing to many / any of the car's sensors. It you were to do so, it is important to protect those signal lines into your signal conditioning circuitry.

JC