Um, Hi

     Hi.

      I retired "ALBERT" last week.  He did fine work, but we've got steam drills an integrated control/alert system now, and just in time; the wiring on the old rocking mercury switches that made those "aircraft lights" (not their real name: they're "Code Beacons") blink had almost worn though the insulation.

     (ALBERT's job was checking to see if the Code Beacons were blinking or not, accomplished by means of a current transformer/rectifier per light, each one producing a little zot of DC every time the light flashed.  A clever circuit called a "missing-pulse detector" checked that those little zots were arriving, and not too far apart; if they stopped, got too far apart, or stayed on, the missing-pulse detector nudged a NAND gate and the NAND gate told an optoisolator. The optoisolator told the remote control, the remote control told the operator on duty and he picked up a telephone and told me.  I'd tell him, "Okay, I'll check on it," and then start looking for my car keys and a change of socks.  One minor problem was that the newer Code Beacons use LEDs, which take a lot less current for the same light output.  ALBERT was never quite sure about them.)