Hi I'm Brian, from Pittsburgh. I was hoping you guys would let me tap into the knowledge banks here.

I have been given an assignment for my apprenticeship classes (5th year), where I need to draw a daigram. the diagram must have three momentary pushbutton switches, then operate a lightbulb. the lightbuld will come on only if the switches are pressed in the proper order.

This was simple. three switches in series with holding relays.

To go beyond the basic assignment, for my own enlightenment, I would like to generate a lockout condition if the switches are pressed out of order. I have been trying to pull this off for hours now, I just cant seem to place it, nor can I find any resources online. I'm gettin frusterated!

What I'm asking is that someone direct me somewhere that I can see what this curcuit should look like, or atttach something that would help.

I REALLY appreciate any help you guys give me, thanks!