[BwanaNdege]

This is not the exact one, IIRC, but looks like a good design, also.

"How the Vortechs System Works "

This version looks very efficient & cost effective.

"How the CDS System Works "

[1010RD]

Thanks. That’s how I suspected they’d work. I wonder what the cost effectiveness is? I’m not certain the ‘problem’ justifies the solution.