Christmas Light Display Cabinet

Equipment in the cabinet runs the entire light display.  All the computers, power supplies and timers are located there, except for the power triac boards and 8 relays mounted in a remote cabinet outside.

This cabinet is a used RTU (remote terminal cabinet) cabinet that was disposed of when a gas plant closed down.  Since I was in charge of disposal, I brought the cabinet home!  Otherwise it was headed for the scrap metal yard.

The pictures show the front and back of the cabinet.  The front obviously has all the user controls and simulation panels, hidden behind a smoked-glass door.  The back has the power supplies, wiring and tripping relays.

Most of this used to be mounted on a 3/4 inch sheet of plywood which I had to haul around every year to get it ready for the season.   With this new cabinet, installed in 1998, everything is permanently in one place.  I have a schematic wiring drawing of all the wires and I placed equipment so that trouble-shooting any problems would be easy.

In 2001 I added a PC-type computer and monitor, with a special SVGA cable hooked up to another monitor outside for running a Power Point presentation.  I wrote a little Visual Basic program that counted down in big letters from 60 :00 minutes to 0.00.  At that time, the computer generated a pulse out on one line of the parallel port that triggered a small 5 volt relay that triggered a bigger relay that triggered all the rest of the display (which itself included 8 relays).  Power came from a number of different circuits to balance the load, but in the cabinet below, only a little bit of AC power was actually consumed.