In the 1970s I got to visit my grandparents every summer. They had a big house, and sometimes I liked to play in the large basement. My grandfather’s wood shop was down there, though I didn’t spend much time in it when he wasn’t there working on something. There was a lot of disused furniture, books, clothing, and all manner of other stuff.

One day I happened onto a box containing an electronic kit, with components packaged into plastic blocks with magnetic contacts. The blocks could be assembled onto a metal plate to form various interesting circuits, with many examples in the manual. I spent several hours playing with it, then my grandmother found me. She was upset because she had bought it to give me as a Christmas gift, and thought she had hidden it adequately. I didn’t get to play with it any more, and I didn’t receive it as a Christmas gift.

I didn’t remember the name of the kit, and I’d never seen one again until today, though I did get a Radio Shack 100-in-1 Electronic Project Kit a few years later.  A friend got one of the kits with plastic blocks with magnetic contacts recently, and it turns out that it is a Lectron kit.  They are still made and sold in Germany.The Lectron blocks look exactly like what I remember from the basement.    In the late 1960s and early 1970s, they were imported and sold in the US by the Macalaster Scientific subsidiary of Raytheon. The Decode Systems web site has a review from the September 1967 issue of Electronics Illustrated.

There are some other similar products, such as the Elenco Snap Circuits (available from Radio Shack), and for digital logic, Logiblocs.  Bloc-Tronic was similar to Lectron, but was apparently not very commercially successful, as it is extremely rare.