I was cleaning out my files last week and ran across this.  It is a kitchen timer I made for my mom a long time ago…I am guessing early 80s.  The thing that made me laugh was not the diode logic but that I labeled it “Timer for Mother.”  Why did I say “Mother” instead of “Mom?”  I call her “Mom” now and it feels like I have all ways called her that.  She is 97 and still mentally sharp.  She does not cook any longer so does not need the timer…I still have it though.