Minimalistic Circuit Design

[David Terrill], whose exploits we have covered before, has shared with us his techniques for building circuits without a prototype or bread board. [David] managed to incorporate a Dual D flip-flop at the heart of the circuit, as well as an impressive number of transistors, diodes, and other passive components. Unfortunately, the circuit diagram is a little low resolution to really make out the real function, but based on the components, our best guess is a two-output blinking circuit. Maybe for an encore, someone out there will build a circuit built entirely around a battery so that it can be a self-contained system.

Let us know if you have a better copy of this schematic, or a guess at what the circuit does!

30 thoughts on “Minimalistic Circuit Design

  1. You guys look at this and see beautiful. I certainly appreciate the skill involved, but when I look at it, I think soldering burns and extreme frustration :P. Imagine all the space that was saved making this in 3 dimensions rather than laid out flat on a circuit board.

  2. I have built switch mode power supplies from scratch like this, then sealed them in custom sized copper boxes filled with oil.

    Extreme frustration pretty much sums it up, but it was cheaper and more rewarding than buying high power density smps’ back in the day.

  3. the 7474 has all the 2nd D flipflop I/O’s to ground, and the following on the first D:
    pin 1 is CLR,
    pin 2 is D, wired to pin 6 Q’
    pin 3 is CLK
    pin 4 is PR tied to VCC
    pin 5 is Q out
    pins 8-13 tied to 7 GND.

    The first bus of the transistors is Vcc, but after that i get lost in the resistors and etc.

  4. In the same spirit, here’s a 556 (pair of 555)’s wrapped with passives. Wires lead to a solar cell and a tiny speaker. The whole thing wedges above the lightbulb in my old refrigerator. If the light stays on for 2 minutes, the speaker buzzes. One 555 is the delay, the other is the buzzer.

  5. @Camille Goudeseune: Awesome! Now if I had built one of those a month ago I would have saved some dairy products. Fridge got left open over night and I didn’t think it was going to come back to life, some strange noises and 2 hours later and the fridge was working again. Would really enjoy some additional photos!

  6. @Skitchin: Glad you like it. Click on my name in this comment for a tarball of all 6 photos.

    The passive components were random junkbox finds. Layout was improvised one component at a time.

    Be warned that the packing tape covering a cheap photocell will eventually melt, when contacting a lightbulb.

  7. @DerAxeman: I’ve just finished an astable mv. built with SMDs, 1206 for the resistors and SOT-23 for the transistors. The caps and LEDs were toaster-ovened off of whatever board they used to be on. It took about 4 hours to build, and ended up about the size of a dime, and not much thicker.

    To me, it’s not as visually impressive as the Terrill’s work, since most SMD parts are black. I’ll stick to toaster-oven reflow for future work.

    There’s a pic. at

  8. We use to call them cordwood modules, or welded wire modules. A piece of mylar top and bottom with holes allowed very large circuits to be built. Component leads were left long on the bottom layer for pluging into large circuit boards which then could be plugged into mother boards. Quite common in the old days.

  9. This was (circa-1970s) commonly called “dead bug” construction, and is pretty much the same as (1915-1960) vintage bread-boarding, minus the plank of pine (aka the bread board).

  10. the site has been updated with a description and more pictures. the circuit adds din sync to a drum machine that was thought to be unsyncable. he’s still not giving up the schematic.

  11. Years ago there was a hand-held frequency meter construction project in Popular Electronics (IIRC). It was made of DIP package parts that had the packages glued together with model cement and then the connections were made with thin insulated wire. The readout was made of 7-segment displays. Then layers of acrylic plastic were glued to form the case.

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