Version 4: Scare LED display
Electronic

555, 4017

Controlled by a 555 timer at 5kHz. Counter 4017 has ten outputs. Only six output are needed (Q0-Q5).

The Q6 is connected to the reset (MR Mater Reset). We have 4 groups of diodes.

The diode A which is connected to the outputs Q1, Q3 and Q5.

The group of diodes C are connected in series and the outputs Q2, Q3 and Q4.

The group of diodes D are connected in series and at the output Q4 and the diodes of the group B are connected in series to the output Q5-9.

Which gives as display the following combinations:  

Output of
4017 at higt

number
of dice

Del = On

A

B1/ B2

C1/ C2

D1/ D2

Q0 et Q5-9

2

 

●●

 

 

Q1 et Q5-9

3

●●

 

 

Q2 et Q5-9

4

 

●●

●●

 

Q3 et Q5-9

5

●●

●●

 

Q4 et Q5-9

6

 

●●

●●

●●

Q5

1

 

 

 

 

B2

 

C1

D2

A

D1

C2

 

B1

 

1

2

3

4

5

6

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 Required parts :

 

• resistors: 330 × 3, 470, 10k × 3

• 555 timer IC, Ex. NE555

• capacitors : 0.01μF, 0.1μF

• 4017 counter IC

• diodes: 1N4148 × 6

• Support de circuit IC: 8-pin, 16-pin

• on/off interrupter

• LED: Red 5mm diameter × 7

• Pushbutton

• battery clip pour 9V PP3

• strip board (Vero board): 20 rows × 22 holes

 

 

To make a diagram with a logic circuit simulator the diodes are replaced by OR gates and the 555 by a pulser which gives :

 

 

 

 

 

 

 

 

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