A nice circuit board tribute to Forrest M. Mims

Check out this rather nice idea: its a circuit board tribute to Forrest M. Mims, the American magazine columnist, and author of the popular Getting Started in Electronics and Engineer’s Mini-Notebook series of instructional books.

A nice circuit board tribute to Forrest M. Mims

Star Simpson, a maker and former electrical engineering student at MIT, has worked on a series of special circuits. The initial release of three circuits (in kit form) code: the Dual-LED Flasher, the Stepped Tone Generator, and the Bargraph Voltage Indicator.

You can read about them on circuitclassics.com:

Forrest M. Mims III is a trusted name in the electronics world for good reason: his charming and engaging texts have drawn millions of people into the world of electronics for the first time. I have brought three of those hand-drawn circuits projects to life by creating an exquisitely designed series of finely crafted and highly detailed boards. These are the Circuit Classics. They make a great gift for a first-time learner, an expert tinkerer, or even just as a fun conversation piece for your desk.

Thanks to Mike Meakin for highlighting this one. It was on the crowd funding website Crowd Supply and the $9,750 goal was smashed, by raising $45,233 (from 559 pledges of support).

“They make a great gift for a first-time learner, an expert tinkerer, or even just as a fun conversation piece for your desk,” the site says.

forrest mims 2A nice touch is that the reverse of the boards feature a description of how the circuit works taken directly from Mims’ books and even how he drew it in mechanical pencil. (Mims is pictured, right, with a board.)

There are also extra large solder pads on the back and a set of test points to let you probe the circuit to see whats going on electrically at that point. There are even layers of copper to replicate the notebook lines that would have been in the oringal books.

If you’re interested, you can pre-order them for $39 (or $$ for the set of three) and the kits are apparently beeing sent out now and they cost to buy.

Each kit includes:

  • Printed Circuit Board (PCB): Includes the circuit itself, the circuit’s schematic, and a description of the circuit, all in Forrest’s iconic hand-drawn style, traced directly from his books. (Prototypes are OSHPark purple, but the final production run will be blue.)
  • Through-hole Components: All the components you need to build a working circuit. Easy to place and solder on the PCB thanks to clear footprints and large, friendly solder pads.
  • Display Stand: made of high-quality blond ash wood, each stand is crafted to let you proudly display your work.

Dual-LED Flasher

For example, the Dual-LED Flasher is described as follows:

This circuit is a rewarding first project — with just nine components you can get the satisfying effect of making LEDs light up and blink. The circuit’s functionality is charmingly complex despite its simplicity. Understanding how it works will provide a taste of the analog side of electronics, and is a fun puzzle!

It has also appeared on Adafruit’s “Ask an Engineer” – see Special guest Star Simpson @starsandrobots ASK AN ENGINEER – 8PM ET 2/17/2016

Features & Specifications

  • Alligator-clip friendly drills form clip points for the power and ground in the corners of every board, and to allow for testing on the bargraph voltage indicator.
  • Top-layer silkscreen tracks copper on the top layer, while bottom-layer copper traces are indicated by the use of negative soldermask. This creates a 2-layer visual effect. New learners would once have learned about electronics by trying to “read” other boards, holding green 2-layer boards up to a lamp to visualize all the electrical connections. This allows for recreating the experience in a much friendlier way.
  • Forrest Mims’ pencil-drawn schematic accompanies on the right hand side of each board, visually aligned to easily connect physical and logical hardware.
  • Copper tracks beneath the schematic replicate the notebook lines from the book.
  • Every board features Forrest Mims’ signature
  • Solder pads designed to be extremely pleasing to solder
  • Explanations of how each board works accompany on the reverse side of the board
  • Book and page number citations to make it easy to look up the original
  • Board Dimensions: 5” x 3.5” x 0.062”
  • Board materials: FR4, blue soldermask, ENIG (gold) finish
  • Power: alligator clips included; powered by, for example, a CR2032 coin cell (not included)
  • Test Points: grabbers, and scope probes
  • Stand Dimensions: 5” x 2.75” x 1

PCB designs with a twist

On the subject of PCB design – also flagged by Mr Meakin – check out this Bob Pease tribute – another functional circuit board tribute!

More unusual PCB design was provided by TopoR, an EDA programme characterised in part by an absence of preferred routing directions.

See also: Is This Three Pin Adaptor for Real or Just Artistic License?



  1. Thanks BringBackGermanium

    Nicely-spotted, times two.

    So two diodes for the circuit above and a resistor for wikipedia?

    Makes me wonder just how good Mr Mims was at everything else.

    BTW, ignoring the effect on power consumption and timing of the B-E junction reverse-conducting, is the base-emitter junction really in that much danger? My poorly-tuned intuition tells me the B-E junction is tough enough to look after itself – although 22uF is quite a bit capacitor.
    I am worrying myself now, does the transistor turn on when its base is conducting backwards?

  2. BringBackGermanium

    The PNP transistors suggest that perhaps this circuit originated in the days of germanium transistors. They would have worked. With silicon planar transistors it would not be advisable to supply the circuit with more than 5V. Anything higher, and there is a risk of blowing the base-emitter junctions or at least degrading the transistors. it is not the first time I have seen this error.

    Mims’ Wikipedia page shows another incompetent circuit, a flasher in which there is nothing to limit the base current of the second transistor.

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