Decimal counter.

With two IC's and a 7-segments LED-display one can build a decimal counter that counts pulses from 0 to 9. A possible application of this is counting the number of products that pass a certain point of a production line. The counter can be cascaded to count any large decimal number.


The total diagram consists of a BCD-counter, a 7-segments-decoder and a 7-segments LED-display.
The counter is in a C-MOS IC of the type 4518. It contains two 10-counters, a and b. Each counts binary from 0000 to 1001 and then returns to 0000. We only use one of them; b.
The 7-segments decoder is in the CMOS IC 4543. This IC turns a binary number of 0000 to 1001 into seven binary outputs, in such a way that on the display they show the numbers that can be seen on the picture.
The LED-display HDN1131 (print the data sheets) needs resistors R to limit the current in each diode. For this type, that should be about 2 mA.

Read more in the pdf-file

--> Decimal counter (pdf-file)

Data sheets of the IC's used:

--> Data sheets of the HDN1131
--> Data sheets of the HEF4543B
--> Data sheets of the HEF4518B
--> Data sheets of the HEF4011B
Decimale teller op print