The time bandit clock uses four salvaged fruit machine reels to display the time. The reels are modified with binary encoders. These cosist of a punched card disc which interupts an Infra Red light source. A binary word is generated with phototransistors reading the holes in the disc.
INFRA RED TRANSMITTERS AND RECEIVERS
THE PUNCHED DISC AND ENCODER CIRCUIT FITTED
The binary word comparators give a TRUE / FALSE output, depending on the reels matching or not.
BINARY WORD COMPARATORS
These TRUE / FALSE outputs go to the control circuit.
Here a control pulse from the clock, every minute, initiates a spin of the reels by enabling clock pulses to the stepper drives.The reels spin freely for 2 seconds. Then the control waits for a match from the binary comparators and stops the reels. The timing for the sequential reel start is controlled with a PIC. This also enables the lighting and controls a sleep mode where the clock keeps time, but the reels are stopped and the illumination is turned off.
COMPLETED CONTROL CIRCUIT
REEL ASSEMBLY ILLUMINATION
The control circuit also switches supply voltages to the stepper drives and encoders.
The base of the clock encloses all electronics.