Here is something I found from one of my readers at superpositioned.com. This is a new site that has some good projects. I encourage you all to check it out. Anyway, he found a binary clock that is built entirely from counters and LEDs. This is a neat project to do, but is pretty complicated. In his article he obtains his 1Hz cycle trough using a 74HC14N Hex inverting Schmitt trigger, two 4-bit counters, and a 4 input and gate to convert 60 Hz electricity cycles into a 1Hz clock cycle. This does work, and may be the easiest way, but it has limitations. If done this way it has to be plugged in. If you wanted to use a battery to run this clock, then a much better way is to use a 32,768 clock crystal. This is the same crystal that is used in all wristwatches, and is very accurate. You would then connect the output of this to a 16 bit counter, and check bit 15. If you use this bit as your 1 Hz cycle, you have a very accurate timer. Once bit 15 goes high you simply reset your counter.
John did a very nice job on his clock. I am impressed that he built his own powersupply, and gets his power from AC. He drops his 120V AC down to 9VAC using a transformer (Jameco part #100061). He uses a bridge rectifier to convert the AC to DC, and then uses a 7805 5v Regulator. I want to build one of these using a microcontroller. It is much easier this way, and you can do most of the work in software. You use one pin to oscillate every second, one to oscillate every minute, and another to oscillate every hour. You then connect them to their own counters and connect them to a row of LEDs. You can make one LED oscillate every second. You would need 6 LEDs to count for the minutes, and you would need 4 to count the hours. Here is a good pic of how to set it up. You don’t need to use 24 hour time, and don’t really need to keep track of AM and PM. This link can be found at sorgonet.com. This is a binary clock that is run from a parallel cable connected to a computer.
But back to the clock I am talking about. This site give a very good tutorial on how to do everything, and gives good schematics. Check it out at gimpfaq.org.
I have a big test coming up on Monday, so won’t be updating till then. Come back and I will explain more on how to use a crystal oscillator. Sorry if my site went down some last night. I have been having ISP problems.
Greg
5 Responses to “DIY Binary Clock”
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David, thanks for that. I forgot to mention that the AC 120v is first brought down via a transformer. I have def. seen the magic smoke before… haha
DJcrayon, Thanks for that. I know exactly where you are sitting, and know how tough it is. I wish I could of had some better resources when I went through. I am glad I can help. If you ever need help, I would be happy to help out.. just send me an email.
Mark is right, the 60 Hz from the power companies is accurate, and I forgot to mention in my article why I did not like using the AC as my timing device. I want to make a battery powered clock, and for this you would need a crystal circuit.
Todd, I will put a link to the schematics on my site. It is on the last link at gimpfaq.org. I will post the schematics of the clock that I build when I write up the article.
Hey John, Welcome to DIY Live. I REALLY enjoyed your article. I think you did a fantastic job with it. I really hope I did not offend you in my article. I see it is mistakingly a little harsh. I will reword it.
No offense taken. Several coworkers had the same suggestion when I was still breadboarding the clock. I just stayed with what I felt comfortable with.
I’m glad you enjoyed the article. As an aside, I probably never would have pursued building a binary clock if I could have just bought one. However, ThinkGeek wasn’t selling them yet, and while ElectronicsUSA.com and HobbyTron both sold “binary” clock kits that you can buy fully assembled, they are BCD clocks — not binary. The only place I found that offered fully assembled real binary clocks was ESP Technology (http://www.esptec.com/Clocks/RoundedEdge.html). These clocks looked nice, could be ordered with any color LEDs and orientation, and were priced quite reasonably. Unfortunately, they appear to no longer be in business, as they never responded to any of the email inquiries I sent. Thus, if I wanted a binary clock, I would have to design and build it myself. True story.
Thanks Ernest,
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