Electronic Dice

Description

The IC1 is a 555 timer IC is connected for, Astable operation the clock pulses are fed to the IC2 via the 10K resistor. The IC2 is a 10 stage counter, output 6 (pin 5) is connected to RESET (pin 15), thus giving us a 6 stage counter , outputs 0 to 5. The 6 of the LEDs are connected as 3 pairs, thus requiring 4 different signals, these signals come from the 4 transistors, which in turn are connected to the necessary outputs of the IC2. Where a transistor is operated from more than one output, diodes are used to avoid a short circuit situation between outputs. Pin 13 of the IC2 (INHIBIT) is connected to +ve via a 100K resistor to stop the counter from advancing, however pressing the S1 [START] button will connect pin 13 to 0V line and allow the counter to advance, hence, throwing the dice. The circuit supply can use a 9V battery or external pack 9 until 12V. The D7 until D15 LED’s connected as Fig.2 to make a dice.

Circuit diagrams

Circuit diagrams
Circuit diagram

Part list

  • R1-2=2.2Kohms
  • R3=10Kohms
  • R4=100Kohms
  • R5.....8=8.2Kohms
  • R9.....5=1Kohms
  • C1=22uF 25V
  • C2=10nF 100V MKT
  • D1.......6=1N4148
  • D7.......13=Red Led 5mm
  • IC1=NE555 or LM555
  • IC2=4017B
  • Q1....4=BC550
  • S1=Normal Open Push switch
  • SL1=4pin connector 2.54mm step
  • BATT=9V battery or 12V ext.