Push Start System

[AK91]

Hi Guys!

I’m new to this forum and pretty new to electronics too. I do have some knowledge of basic circuits etc.

I'm trying to create a push start system for my car, below is what I want the system to do:

The systems will have 3 buttons:

Button A - used to start the accessories
Button B - used to start the ignition and all remaining electrical systems
Button C - used to start the engine

When button A is pressed, the accessories are powered and also enables button B to function. When button B is pressed, the ignition and all remanaing electrical system start and enables button C to be pressed. While button C is pressed the starter motor runs.

When button B is pressed, the car and igniton should turn off and when button A is pressed the ignition, car and accessories should turn off.

I'm sure this is not too complex, I have scribbled a diagram on some paper and will scan it and add it to this post later on. I would like some guidance of how this can be done. I am ordering parts soon and will first test it with a few LED's before sticking it into my car. After all I don't want to mess my car up.

Thank in advance!

 

[alec_t]

Welcome to the forum

After all I don't want to mess my car up.

And your insurance company won't want you to either. In fact, many insurers will invalidate your insurance if you do mods of that sort, since in their eyes it increases risk. Have you fully considered the safety implications? What happens if your circuit fails mid-motorway? If you're "pretty new to electronics" I'd recommend cutting your teeth on less hazardous projects before even attempting one like this.

I am ordering parts soon

That's putting the cart before the horse. You need a fully thought-out design before ordering parts.

 

[AK91]

Welcome to the forum

Thanks for the Welcome!

many insurers will invalidate your insurance

I had thought about that before, but I had also seen quite a few other people do this mod too. I think i'll confirm this with my insurance provider first.

Have you fully considered the safety implications? What happens if your circuit fails mid-motorway?

This is a very good point! TBH, I didn't even come near to ever thinking of this! So thanks for pointing that out. How would you go about preventing this from happening?

I'd recommend cutting your teeth on less hazardous projects before even attempting one like this.

I have done a mod previsouly in my car, it was just a few switches to power amps with relays on them and it all seems to be working just fine for almost a year now.

I think I'll go ahead and still create this, but as a prototype.

 

[alec_t]

How would you go about preventing this from happening?

By not building such a circuit . I'd be surprised if your ignition and starter systems weren't monitored/controlled by the engine management computer and I wouldn't want to mess with that.

 

[AK91]

By not building such a circuit

Haha! True, but I gotta give it a try, at least as a prototype!

I'd be surprised if your ignition and starter systems weren't monitored/controlled by the engine management computer and I wouldn't want to mess with that.

It is, earlier today I tried starting my car with my key wrapped in foil (not the actual end of the key just the chuncky body) and the car started and immediatley shut off. Tried it again and same thing! Removed the foil and worked fine.

Do you know any easy to use software that I can use to simulate circuits? I've downloaded a few but they are so complex!

 

[crutschow]

..........................

Do you know any easy to use software that I can use to simulate circuits? I've downloaded a few but they are so complex!

All software to simulate circuits is reasonable complex since it is a complex task. Most of them are based upon the Spice analog simulator developed at Cal Berkeley. One verison used by many on this forum is LTspice, which is a free download from Linear Technology. It has a somewhat steep learning curve, as do most Spice simulators, but once you are familiar with the basics its quite straight-forward. There is a good tutorial available and many sample circuits to help you get started.

Of course you need a basic understanding of Ohm's law, series and parallel circuits, transistors, and the frequency characteristics of inductors and capacitors to help make sense of the simulator results of any circuit you simulate.