Binary clock gallery

A collection of binary clocks, based both on my design and others. If you have built a binary clock, please contact me to send me a picture.

Did you come to this page just to ogle pictures of binary clocks without first understanding their design? Do you also buy Playboy just for the pictures and not read the articles? For shame! Go to my tutorial page to learn how they were made.

My first binary clock

  • binary clock on a breadboard
  • first attempt at a binary clock

Once I learned the basics of electronics, I was eventually able to breadboard a binary clock. Note that the picture shown below is not of the original design. Originally, I fed the AC sine wave directly into the counter chip just as Marshall Brain showed in his schematic diagram. This worked, but the circuit was sensitive to noise on the AC signal. I later improved it slightly by filtering it through a capacitor and a Darlington transistor as shown in this schematic diagram. This picture also shows the 9V battery backup and a filter capacitor that I did not add until later.

What is the use of a binary clock on a breadboard? (That is a redundant question to many people. To them, what is the use of a binary clock at all?) I wanted something I could display somewhere, so in January 2002 I started soldering my binary clock on some protoboard. I bought a cheap 5x7 wood plaque at a local craft store, stained it with some leftover wood stain, and mounted the protoboard on the plaque. (Afterwards, I realized that I had mounted it crooked!)

My second binary clock

  • second attempt at a binary clock (display board)
  • second attempt at a binary clock (logic board)

I built a second binary clock for my brother and gave it to him for Christmas 2003. This time, I used a Schmitt trigger to get a clean 60Hz square wave for the time base. I built the clock on two circuit boards: a display board and a logic board. The display board also has a spot for an optional CR2032 button cell battery (covered by a piece of yellow electrical tape in the picture). It helps the clock keep its place when the power goes out. PCB-mounted buttons at the top right set the hours and minutes. To save space, I eliminated the transistors used to drive the LEDs and let the logic chips power the display directly.

A transistor at the bottom right corner of the logic board blinks the LEDs at 60Hz for a 50% duty cycle. It also keeps the LEDs off when the power goes out. Since the circuit is completely exposed, I protected the clock with a fuse. Should something cause a short, the fuse blows, and power is cut to the board.

I sandwiched the binary clock on a wooden clock frame. It is a keepsake clock kit I found at a local craft shop. It comes as bare pine pieces that you paint, decorate, assemble, and give to grandma. I stained the wood with red mahogany stain, then put on coats of urethane until the finish was completely smooth.

My third binary clock

  • third attempt at a binary clock
  • third attempt at a binary clock (daughterboard)

After reading this article on Slashdot, I wanted to try creating a custom PCB. I had planned to design one PCB for the digital logic and a second board for the display LEDs. However, I realized that because I am not limited to preset component spacing and orientation and because I do not have to leave room for point-to-point wiring, I could pack things together tighter and fit everything on a single PC board!

The overall size of the board is 3.9x3.1 inches, which is the largest size that the free version of EAGLE let me create. However, that is enough room to get almost all the components I wanted on there. I did have to move the time set switches to a daughterboard to save space (all board interconnects are made through header pins), and I also had to eliminate the backup battery. To compensate for no backup battery, I used bigger capacitors. They can supply enough voltage to hold the counter chips for about two seconds when the power goes out.

I ordered the PCB from Custom PCB. FedEx delivered my order about a week later. Unfortunately, once I assembled the board, I discovered a bug in my design. (My fault, not the manufacturer's.) The hours counted from 0 to 27 instead of 0 to 23. Fortunately, I was able to correct the problem by scratching through a trace and shorting two IC chip pins together. (By the way, I have one fully assembled board left that I would be willing to sell. Contact me if you are interested in obtaining it.)

Once again, I sandwiched the binary clock on a wooden clock frame. I stained the wood with a walnut stain and ran the wires between the logic board and the daughterboard through a hole I drilled in the frame. (A coworker pointed out that because the board has solder pads on both sides, I could have soldered the header pins on the reverse side to hide the wires from view entirely.) I have this one on my desk at work as a pretentious geek status symbol.

From Thomas Carpenter (UK):

  • inside
  • outer case

Here Are the pictures of my clock. One is of the inside, and the other is the outer case.

From Luca Morisi (Italy):

  • front
  • back

Qui di seguito potete trovare due immagini del prototipo dell'orologio binario di cui ho scritto nel post del 9 ottobre. Le immagini raffigurano la parte frontale ed il retro del prototipo saldato su basetta millefori.

Unfortunately, I cannot read Italian, and Google translates it badly. Here is a rough approximation of what I think he says:

Here are two images of the binary clock prototype of which I wrote in the post of October 9. The images are of the front and the back of the prototype on perfboard.

From Paul Grusovin (Australia):

  • inside
  • Jarrah and Alpine Ash box

My son Andrew found your circuit about two months ago and we finished it yesterday. Attached are two photos of our binary clock.

I had a few old DC plugpacks lying around, but no AC. Solution: hacksaw open a DC plugpack, pull out the rectifier diodes and caps, resolder, hot glue together. The 4082N AND gate was not available, so I used a 74LS20 NAND with a 74LS04 inverter. The three banks of 5mm LEDs were mounted directly onto the front panel. (A 5mm drill hole gave a push fit.) Junked dual inline pin connectors were used to connect LEDs to the main board—a 3.6in x 4.0in piece of Veroboard. Everything fit into a 13cm x 8cm x 11cm Jarrah and Alpine Ash box we purpose made.

From Marc-Henri Poget (Switzerland):

  • the circuit wired on a piece of stripe board (Veroboard)
  • white LEDs on the breadboard for debugging the circuit
  • the final result in its wooden box

I've completed my binary clock project. A 4060 IC and 32.768 KHz crystal produce a 2 Hz square signal. There are the 3 4024 ICs used for the seconds, minutes and hours. Around these ICs, there are the base resistors for the LEDs driving transistors and the diode logic for the reset. The condensator is used to manage the manual reset which is fed to all the 3 counters using also diodes to avoid short-circuits. To setup time, there are switches that allow to select the input clocks of the minutes and hours 4024. By default, the input clock is coming from the previous 4024, that is the seconds IC feeds the minutes IC and the minutes IC feeds the hours IC. The switches allow to feed those ICs directly with the 1 Hz signal coming from bit 0 of the seconds IC. As the 4060 produces a 2 Hz signal, the 1st bit of the seconds IC is not used and all the bits are shifted. Each LED has a BC547 transistor and a 100 ohm resistor (not shown here, added later) to limit the current to 20 mA. To limit room on the circuit board, the driving transistors are mounted closed to the LEDs.

From Tatpong Cherdjareewatananun (Thailand):

  • seconds display
  • finished binary clock
  • finished binary clock

Here are some pictures of my binary clock. I built this binary clock for my Year11 Design and Technology major project and I got A* for it. The display is a spreyed PCB with ultrabright blue LED covered in a test tube. The body is made out of MDF. There are buttons for minute and hour setting on the side.

From Jeff Pinter:

  • front
  • back

Here are a couple of pictures of my first binary clock. I used a Radio Shack ckt board and got my components from Digi-Key.(I really like that place). I make a crude box out of clear plexy and made a quick front out of some red label stock i had laying around.

From David Wharton:

  • development
  • front
  • side
  • back

Here is my Binary Clock built from using your Schematic. It was for my Year 11 Electronics course at GCSE level, and I got an A* for it. I built the clock on strip board, used green LED's for the time, and some large pushbutton switches to set the time. I had to modify the circuit in two ways, so it runs on 50hz, and I had to use the 74LS21 logic gates as the other gates weren't available. I added a makeshift case to the project, just two pieces of clear acrylic attached on to the clock, with a hole for the 9V 500mA transformer. The total cost of my project came to around £10 (with the majority of the components bought from ebay).

Inside the ThinkGeek BCD clock

  • ThinkGeek BCD clock
  • ThinkGeek BCD clock

The most common binary clock is the Powers of 2 clock, which is manufactured by Anelace and sold by ThinkGeek. I bought one back in 2002. I was still tinkering with my own binary clock design at the time, and I figured this was the perfect replacement for the meantime. (Well, almost perfect, since this clock is BCD and not real binary, though apparently recent versions can also display in true binary mode.) However, once I finished my binary clock, I decided to crack open the ThinkGeek BCD clock and see what was inside.

What I immediately noticed was that there were no 5mm LEDs on the board. With the exception of a few components, everything was surface mount. The "LEDs" on the red plastic cover were just lenses for the SMT LEDs. I wondered what the purpose of the bank of diodes was, so I grabbed my multimeter and a pencil.

ThinkGeek BCD clock schematic diagram

D3-D6 compose a bridge recitifer. I can only guess why Anelace chose not to use a discrete component. The output goes to pin 8 of U2, which is the input of the 8L05A 5 volt regulator. D1 and D2 are connected to the AC inputs of the bridge rectifier and generate a 60Hz clock signal. This signal is connected to pin 4 of U1, which is the "brain" of the BCD clock.