Latest project I finished. Designed and built by me including the enclosure.  - Page 1
Forum section: electronics / projects

author: jacamo
author_rank: Contributor
timestamp: October 27, 2021, 03:32:52 am
content: This is a project I just finished and thought I would share and try and get some feedback. Particularly the schematic seems a bit cluttered and was wondering if anyone had some pointers on how to make it more clean looking.I bent the enclosure out of .036in aluminum sheet and what is pictured is my second attempt of making it as I realized the first one had much room for improvement.The picture of the circuit board that is taken apart is my first attempt at making it. I ended up. much like the enclosure, having to start from scratch and do it all over again. The other picture of it powered up is my second attempt which went much better. The issue with the first one was I built the entire thing and then tried to debug it which I learned is not the right way to do it. There were so many issues with the first one due to using strip board and there still having continuity between certain traces. I used a drill bit to break the traces and the one I used was I guess just too small and left some still connected even though they didn't look like it. I ended up after the 6th one I found and corrected on the first PCB to just start over, used a bigger drill bit and to test each section as I built it. Which turned out to be a key thing in making my life easier when it came to trouble shooting it.It uses all 7400 series and 4000 series logic and a crystal for a time base. The first two digits show the minutes and the other two show hours. The LEDs in-between flash once a second. I also ended up wiring the decimal points to light up when the time is latched to show the time has stopped which isn't in the schematic. It will latch when it detects a change from light to dark. There is a reset button and a pot to adjust the sensitivity of the light sensor.I work at a place where my boss has asked me to test how long certain LED light and battery combinations last. I tell him I can just do the math and figure out how long they will last but he is adamite that I actually test the run time. So I thought I would challenge my self and build something that is relatively useful in the process.Overall I am pretty happy with how it came out but see room for improvement. It also took much longer than I had anticipated but it is the first circuit that I had designed entirely by my self from reading datasheets and figuring out how things work. Any feedback is appreciated.

author: RoGeorge
author_rank: Super Contributor
timestamp: October 27, 2021, 10:28:00 am
content: Looks good, very nice!

author: voltsandjolts
author_rank: Unknown
timestamp: October 27, 2021, 11:51:52 am
content: Welcome to the forum!Good electronic and metalwork skills, and you have mastered KiCAD schematics, well done.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: October 27, 2021, 02:04:30 pm
content: '70's Tech-Deco in the style of that Heathkit / Bell & Howell Nixie voltmeter just behind it! Nice!

author: david77
author_rank: Frequent Contributor
timestamp: October 27, 2021, 02:18:18 pm
content: Very nice! I like the style of your clock.That's what I like to see: You designed your project from start to finish. It is not just a board and some wires, it is a usable product. And it is home made. Something you can be proud of. It does not matter that it's just a clock - it is YOUR clock!I'd say there is not much wrong with your schematic, some small details that I personally dislike like unneccesary bends in some nets.

author: jacamo
author_rank: Contributor
timestamp: October 28, 2021, 12:47:52 am
content: Thank you for the words of encouragement!Along with my Nixie Voltmeter (which I actually use for some things) I also have an HP 5221A Nixie tube frequency counter one of my old teachers gave to me. I love when I get to use it because the way the nixie tubes look.The schematic I was thinking I could have just made the properties of the sheet a bigger size to give me some more room. The other thing that really bothers me is the ICs are all different sizes. They all came from different libraries so other than editing each one to match I didn't see any other way to make them consistent.Testing the time long term has shown it to be very accurate. One thing that I have noticed since I have built it is sometimes when I push the reset button a 1 will appear in one of the digits. Usually the second digit but I have seen the third and fourth also do the same thing. I just push the button again and that clears the digits but I was wondering if anyone had any ideas on why that might be happening? I don't really see how one could be affecting the other.Thanks