automotive hard

[fatkatie]

I'm an electronics technician so I have a handle on the basics.

I want to build a security device for my car. Given the horrible environment, my first thought was to implement the logic with small, cheap dip relays; still might.

But using logic devices, simple msi gates ect, would be nicer. It would be more flexible. Question is, how do they build such robust electronics used in automobiles? (Car starts at -20 and radio plays; dead battery and charges and heat!) I see there are components that are rated for such use, but I think it is that, along with industrial level designing, that will lead to success. Is there a good place to read about how these electronics are designed; the rules and practices and ...

(I'm amazed car computers are so reliable)

Thank you.

 

[Kiwi]

Most electronic components seem to have more issues with high temperatures, rather than low temperatures.
Low temperatures can also put a bit of stress on the copper links on circuit boards due to shrinkage.
Vibration is one of the biggest issues in automotive applications.
Another issue is the varying voltages between engine cranking and charging, eg 10v - 15v.
Also have load dump issues and inductive circuits switching off and on.

There are components that are specially designed for automotive applications, eg IRF1405 Mosfet.