|Principle||The same as the clock at
Time counted by number of balls in 4 trays.
The ping pong balls are lifted by an air fan.
|Building material||Mainly plywood. Balls are lifted in a plexiglass tube.
The complete clock is mounted on a wall.
|Number of trays||4 trays. A new ball arrives every 2 minutes.
Two trays count 2-minutes, 5 x 6 = 30.
Two trays count hours, 6 x 4 = 24.
|Fan arrangement||Low noise 12V fan with just enough power to lift a ball.
Electromagnet controlled entry mechanism for balls.
|Electronics||Crystal oscillator timebase.
Microprocessor controlled functionality. Microchip PIC16F84 microcontroller.
Everything, including fan powered through ordinary 12V AC/DC converter.
|Project schedule||Start january 1998.
Finished may 1998.
Last modified 5. nov 98