Sunday, September 23, 2012

Short a pin? There ain't no more up!

Picture Kentucky Coal Miner on the phone to the maker of their Man-Hoist ("Coal Miner" for open air elevator, beats any Amusement Park ride, only next to the 'Man-Trips', the Roller-Coaster like ride that takes you into the Mine, where you may lose your head at any moment).

Our Hoist only goes up. We've run out of cable, it is all on the spool. There ain't no more up!

I'm sure you have experienced the frustration of needing just one more pin on your Micro. Here is why you don't let the Boss force you into take shortcuts to increase company profits, in the shortsighted short-term. Seems the Hoist designers used two inputs one for Run/Stop and one for Up/Down. Up/Down faulted to 'Up', no mater what you wanted it to do, you only went up.

They should have used four inputs, Run, Stop, Up, Down. Seeing both Up and Down asserted simultaneously would then signal a fault.

The morale of this design tip: Do not take short cuts, people ultimately pay the price. Warrant Repairs are expensive when you have to travel to the mine.