Bar-Graph Counter - Electronic Circuits Projects Diagrams Free

captainkirksdog · 14th December 2003, 08:52 AM

Hi,
I need to make a 0-99 event bar-graph counter. I have tried to use two cascaded 4017 decade counters but I can't get them to behave properly. The first one counts 0-9 then it has a carry-out to the second to count ten, twenty, thirty, etc. The problem I keep getting is the second counter always has the tens LED on when I power up, then when the count on the first reaches 10, it increments the second counter to twenty. How can I inhibit the second counter until the tenth count? Any thoughts? Thanks.

Roff · 14th December 2003, 08:41 PM

I didn't try to analyze your problem, but I found the schematic below in the TI CD4017 datasheet.

Russlk · 15th December 2003, 01:09 AM

A power on reset R-C would stop the tens output from starting from 10, but since the 4017 clocks on the rising edge, the tens counter will light at the 5 count unless you use the circuit Ron showed.

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15th December 2003, 01:09 AM	(permalink)
Russlk	A power on reset R-C would stop the tens output from starting from 10, but since the 4017 clocks on the rising edge, the tens counter will light at the 5 count unless you use the circuit Ron showed. __________________ see my website: www.geocities.com/russlk