Essential Electrical Systems

[Altairahmad]

Mods please move this post if this is not the right forum.

background info is that we are trying to make a prototype car for Shell Eco Marathon 2010. The basic aim of this competition is to try to get a car build which can do maximum mileage.

I am here because there is a condition of submitting "drawings of electrical system".

What we have no idea about is that what exactly are drawings of electrical system like its just one drawing showing all the electrical systems or what ?

And secondly we need to know the very very very essential things without which a car can not operate espaically any eelctrical control systems. Can you please help us listing them.

[MagicRat]

It depends on the engine. If you have an older diesel engine, with a mechanical injection system, you do not need any electrical system at all. I used to have a Bomag one-ton gravel roller/compactor, which was diesel-powered with a crankhandle starter, and had no electical system.

I have also jury-rigged older Ford diesel pick up trucks so they could run without any electrical system at all.

But, lets assume you have a car with a gasoline engine and an electric starter.
The minimum electrical system you need is:
- an alternator (electrical generator),
-battery (to store power to run the starter),
-the starter motor
-a starter motor soleniod (they are often attached to the starter motor),
-an ignition system*
-an ignition switch,
-a starter motor switch (traditionally, both are incorporated into the ignition key)
-and some wire and connectors to hook everything up.

*note, there are several different types of ignition systems. A conventional points-and-condensor system is very simple and easy to assemble and use. However, they have not been widely used on cars in 35+ years. Some industrial and agricultural equipment and some boats still use them though.

An electronic system is more reliable but far more complex to depict in an electrical diagram.

Imo, if you are not building your own engine, use the ignition system that your engine of choice already has.

[Altairahmad]

I am sorry I didnt check back because you replied after a little late and I wasn't expecting any reply then.

What is the difference between starter and ignition circuit? And where can I find model alternator circuits?

[MagicRat]

There is lots of information and diagrams on the internet on these subjects:

The starter circuit energises the starter motor when you want to start the engine.
http://www.samarins.com/glossary/starter.html

The ignition circuit energises the electrical device that creates the sparks for the spark plugs.
http://www.howstuffworks.com/ignition-system.htm

Look here for more alternator info:
http://auto.howstuffworks.com/alternator1.htm