Hila Research Centre

Electronic Project 7

Binary to Decimal Decoding

Devices such as calculators use binary math to do calculations. The binary numbers are then decoded and displayed as decimal numbers. The circuit below uses a binary counter to count the pulses from a 555 IC and then uses a 4511 IC to decode and display the count on a 7 segment LED display.

  • R1 - 100K Ohms
  • R2 - 33k Ohms
  • R3 - 330 Ohms
  • R4 -  68 Ohms
  • C1 - 10 uF
  • IC1 - 555 Timer
  • IC2 - 4518 BCD Counter (4520 may be used)
  • IC3 - 4511 BCD to 7 Segment Decoder
  • 4 LEDs
  • 7 Segment Display (Common Cathode, Radio Shack #276-75)
  • +V    4.8 volts

    • Internal connections to the 7 segment display:

    This project uses the Hila power supply. This supply uses 4 AA rechargeable batteries in series with a 56 Ohm resistor. If you are using a supply without this series resistor, remove R4 and add a 330 Ohm resistor to each LED.

    Project from the Hila Research Centre - http://fox.nstn.ca/~hila

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