Category Archives: EMSL Projects

Maker Faires and the BIYSL

The Annotated Build It Yourself Science Laboratory

This month I’ll be traveling to Maker Faires in Portland, Oregon, and New York City to sign and talk about my book, The Annotated Build It Yourself Science Laboratory. That, of course, is the new, updated version of Build-It-Yourself Science Laboratory, the classic 1960’s hands-on science book by Raymond E. Barrett.

The Portland Mini Maker Faire is being held September 12-13 at OMSI, the Oregon Museum of Science and Industry. I’ll be speaking on the Innovation stage at 11 AM on September 12. This is a bit of a homecoming for the book: Raymond Barrett was the Education Director at OMSI when he originally wrote the book.

The World Maker Faire is September 26 and 27 at the New York Hall of Science in Queens, New York. I’ll be speaking on the DIY stage on both days.

Bonus: During O’Reilly’s Back to School sale (through September 17), you can get the E-book version of The Annotated Build It Yourself Science Laboratory for 50% off using discount code B2S5.

XL741: Principles of Operation


Our two “dis-integrated circuit” kits are the Three Fives Discrete 555 Timer, and the XL741 Discrete Op-Amp. These two kits are functional, transistor-level replicas of the original NE555 and μA741 (respectively), which are two of the most popular integrated circuits of all time.

Last year, we wrote up a detailed educational supplement for the Three Fives kit, that works through its circuit diagram and discusses its principles of operation down to the transistor level. Today, we are doing the same for the XL741 kit, and releasing an educational supplement that explains how a ‘741 op-amp IC works internally, down to its bare transistors and resistors:

XL741 Documentation (PDF)

This ability to peek inside the circuit makes the XL741 a unique educational tool. In what follows, we’ll work through the circuit diagram, discuss the theory of operation of the ‘741 op-amp, and present some opportunities for experiments and further exploration.

You can download the supplement here: XL741 Principles of Operation (1.1 MB PDF)

Additional Resources:




Lemon Plum Jam


The plums on our tree ripened all at once this year! Making this sweet and tart Lemon Plum Jam took care of some of the excess fruit in a tasty way.


  • 4 cups plum pieces (pits removed, skin still on)
  • 2 whole lemons—large meyers if you can get them—cut into pieces (seeds removed, peel still on)
  • Juice of 2 more lemons
  • 1/2 cup water
  • 4 cups sugar

Heat the plum and lemon pieces, lemon juice and water in a pot on medium, stirring occasionally. After about 15-20 minutes, the fruit should be softening. Macerate the fruit in the pot—a potato masher works well for this. Add the sugar. Stir regularly and cook to the desired consistency. To test consistency, put a spoonful on a plate in the fridge. If it’s too runny after cooling for a few minutes, keep simmering and test again after a few minutes.

Makes about 2-3 pints.


If you want to can it for longer storage, Ball has a nice introduction to canning (pdf), and additional resources on their website.

Other fruit preserves from the Play with your food archives:

WaterColorBot and BeetleBlocks

The Tinkering Studio posted on twitter:

BeetleBlocks is a system for enabling people to explore algorithmic 3D geometry by snapping together Scratch-like programming blocks.

BeetleBlocks block programming example

They posted a picture of the finished painting, which looks awesome.

Painted output in the WaterColorBot

Politicians To Poop: A Chrome extension

Politicians To Poop

Politicians To Poop is a new extension for the Chrome web browser that replaces the names of presidential candidates (US, 2016) with the “pile-of-poo” emoji. Options allow you to “poopify” the names of Democrats, Republicans, or both.

Politicians To Poop is available now, for free, at the Chrome web store.


Politicians To Poop

Politicians To Poop

Politicians To Poop

Possible reasons that you might want to use this extension include:

  • You are from outside the US, and don’t need to hear these names every day.
  • You are temporarily overloaded by the amount of poop that the candidates sling at one another.
  • Because it is funny.

No judgement upon any of the named individuals, nor their platforms, parties, or beliefs is either implied or intended. This is intended to be an equal-opportunity text replacement tool, for the good of all humanity.

More information:
This project was inspired by Millennials to Snake People. Much more information including source code, the list of names, and additional attribution is available at our GitHub repository.