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74HC4040 Counter


74HC4040 Counter

12-Bit binary counter

This circuit is the basic setup of a 74HC4040 binary counter it is driving 12 LED’s. to build this first connect Vcc (pin 16) to the +5v rail and Grd (pin 8) to the 0v rail of your project board. You will also need a square clock pulse that is supplied by a 555 circuit you can find this on my other page here. this is a 12-bit counter and will count up to 4095 before returning to 0 if connected to the 1Hz clock pulse that will take just over 1 hour to overclock. To reset this to 0 you can press the switch on pin 11(Master Reset) and this will force all the outputs to 0 instantly.

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555 Timer


555 Timer

astable 555 circuit

This is a 555 IC in the Astable configuration it will give off a square-wave form with a frequency f) The capacitor (C) is charged through resistor (R1+R2) and discharges through R2 only.

( C is in Farads & R are in ohms )

 

 

 

 

Try this:

To build a astable 555 with +/- 1Hz period and 50% Duty cycle you will need:

555 IC,  R1-10k,  R2-150k,  C-4.7uF,  C1-10nF (103)

All this can be bought at Maplin Electronics 

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