74192 clock down counter

Thread Starter

Mark Dominic Boquio

Joined Oct 21, 2015
Hello Sirs! I have a project but I cannot where I did go wrong. I have to build a clock timer using 74192. MM:SS clock where it should count 59:59. But when I am setting the clock, it count until 7 and goes back to 5. And at the time 00:00 it resets which should not happened. Please help!


Joined Aug 1, 2013
Your video is just about useless. The image is too small and fuzzy to see any detail, including pin numbers and joined connections. Please post the schematic as a PDF or image file so it can be read.



Joined Jan 2, 2010
Hello Mark Dominic Boquio

I hope that the enclosed design serves to continue your project.

For simplicity I omitted the 74LS47 decoder and the 7-segment displays; instead I put some Display's called HEX.

If your counter is counting down, 59-00, you should detect when it reaches 99 and at that moment reset the counters to 59. That made the gates that look at the circuit.