Having entertained us for a few years, the synchronous motor and cams were superseded by . . . . .

The Silicon Chip, or to be more precise, 7 - 7400 series chips, a 555 timer & some transistors to drive the lamps.

The 555 timer provided clock pulses at about 10 per second.  This was fed to the clock input of the first JK Flip Flop.  The J & K outputs of the Flip Flop were fed to the clock inputs of two more JK Flip Flops & again to four more Flip Flops thus providing a set of eight outputs, four of which are on at any one time.  These outputs are not powerful enough to drive the lamps so a small transistor is used to buffer the outputs.  Each transistor drives two lamps thus giving eight lamps out of sixteen on at anyone time.

. . . . .    Very Pretty.

Well, the only other development was a similar setup for a star on the top of the tree which just flipped ( and flopped ) between two sets of lights.

. . . . .    Simple,  but effective.

This set-up continued giving good service long after I had left home.

 

History Index

Trees Grow !
     (Dec. 2009)
2008 Display
     (Dec. 2008)
Planning for 2008 !
     (Early 2008)
Here we go !
     (Nov. 2007)
The Big Change !!!
     (2007)
The Night Before
     Light-up (Dec. 2006)
The Tungsten Tree
     (Feb - Nov. 2006)
The Second move
     (Dec. 2005)
Who put that there ?
     (Aug. 2005)
Back in business
     (Dec. 2004)
Click Click Click
     (Dec. 2003)
Rope Lights
     (Dec. 2002)
The Move
     (Dec. 2001)
More Silicon Chips
     (Dec. 2000)
The Next Few Years
     & Chips
The Bug was biting
     (1993 on)
Early Married Life
     (1981 on)
A logical development
     (Dec. 1973 ish)
In the Beginning
     (Dec. 1962)