Bloc-Tronic Electronics Toy

In the “Why don’t they make ’em like that anymore?” category, Bloc-Tronic is a set of electronic blocks that snap together to make a very broad variety of electronic projects.

More Bloc-Tronic Images
The Blocks

Each block has a label on the front and back and a conductive connector on each other side designed to interlock and allow the blocks to be snapped together in many different configurations. Inside each translucent block is an electronic component, ranging from a resistor to a basic amplifier. The blocks are numbered, but also marked with their electronic symbol.

You’ll notice on the picture of the kit that most of the blocks have masking tape on them. I played with this kit so much the print started wearing off the labels. Since I couldn’t stand the thought of not having the kit I started re-labeling the blocks with masking tape.

Full Kit
The Set

This is set ‘D’ which came with 54 assorted blocks, test leads, battery case, meters, microphone and more. According to the case (which has also survived nicely) this is the largest set available. The manual contains 160 combinations for these blocks ranging from a simple circuit with a lamp to a transistor radio.

Add-on sets were available but largely unnecessary with this set. It even looks like you could buy empty blocks to add your own components into the mix.

Click for larger image
The Experiments

This book contains 160 experiments, all possible with Set D. Each experiment has a short description, block diagram, and even the schematic for the circuit. I can’t say I learned how to read schematics from this manual, but it certainly helped when I started to get deeper into electronics.

The experiments get progressively more complex through the book. If one were to complete all the experiments they would have built quite a variety of electronic projects. At some point I may attempt to scan the entire manual.

Better than a breadboard?

While this kit is limited to the components that come with it, Set ‘D’ is sufficient for a great many experiments. The company also offered empty blocks and add-on kits for further projects.

One of the biggest strengths of this kit is the fool-proof way the blocks snap together. Each block connects firmly to the next with a large conductive surface. Even after years of use the blocks still made firm contact and (other than the labels) showed very little sign of wear.

With good instructions, large pieces, and simple, Lego-like construction Bloc-Tronics put a broad variety of electronic projects within reach of a much younger audience than other electronic kits. Even basic prototyping is possible and I have now recovered the kit from my parent’s attic for exactly that purpose.

I’m sure my parents paid a hefty sum for the kit, and took somewhat of a risk that I’d take to it. Whatever the cost, it was worth it.

Where’d it go?

I found only one other reference to the Block-Tronic kit online at Sarah’s Transistor Radio Page. The XTRONIC brand has now been adopted as the name of a Nissan transmission and I couldn’t even find that much information on the parent company Contact-Connect Enterprise.

I’m sure I received this kit sometime in the 1980s, probably around the mid 80s. I can only imagine what a kit would be like today. Imagine an embeded microcontroller, logic gates, synthesis modules, and USB ports!

I don’t know of anything comparable on the market today. The only thing I’ve ever seen that comes close was a homegrown project using Legos which came to me through the Make magazine blog.

Check out my gallery of Bloc-Tronic pictures.

If you’ve owned a Bloc-Tronic set, or have even ever heard of or seen them please leave comment.

Update: I have finally started to scan and upload the Bloc-Tronic manual which is now available on my images site.

electronics, electronic, projects, electronic toys, toy

39 thoughts on “Bloc-Tronic Electronics Toy”

  1. I had a similar kit back in the day. The cubes had white plastic tops with the electronic symbols and clear plastic below. They held together with magnets rather than the mechanical connections on your set. I wasn’t able to find any info on the web, but I ran across this company which looks like a good modern alternative.

  2. I had the same kit as a kid! It was a blast. I remember the projects were really cool (the radio project comes to mind)…then I would start to randomly change or add things to see what would happen. I have been having fun with electronics ever since.

  3. Oh wow! That brings back the memories. I had that kit as a kid, I think I may still have the manual around for it somewhere. I remember the radios you could make with it being pretty good for something so simple.

  4. Hey, I had one too! I totally forgot about that. The blocks were so asthetically pleasing, with that cool translucent green and the silver symbols. It felt like alchemy. I think I made everything in the book, wasnt there a photosensitive block? Was there a lie detector?

  5. Wow! Thanks for all the great responses everyone!

    Glad to know I’m not the only one who had a Bloc-Tronic kit, and I guess I’m not surprised the Make blog subscribers came through.

  6. Heh. I also had a Bloc-tronic kit as a kid, and had a great deal of fun with it. Actually I think I got some expansion set for it as well, and I am pretty sure I can still find it somewhere in my parents basement.

    I remember trying to sell it when I had stopped using it, but the guy never picked it up at the post office, so I got it back.

    I live in Denmark, so Bloc-tronic was also available here back in the days.

  7. this kit is supposedly a copy of the raytheon lectron kit.
    i have set 3 and it has the white modules as another poster stated.
    the bloctronic seens to be more complex.

  8. I had the Lectron kit (as mentioned by kc8adu) when I was young (I had it in the 1970s) and I can confirm that it’s very much the same idea, but I believe the circuit diagrams were molded into the top in a fairly permanent way. The connectors did not protrude from the sides, though they had magnets behind them to make a firm contact. I had the basic kit and two upgrades and I used it for all sorts of things. Much nicer for learning circuit diagrams than the Radio Shack spring-wire things (I had one of those, too) though I’m sure it would be difficult to supply enough blocks to do nearly as many circuits.

    The Bloc-Tronic and Lectron blocks must have been very expensive, especially compared to the spring kits, which usually had a cardboard surface sitting in a wooden frame.

  9. I just bought (at a garage sale) a Basic Set “C” that does not come with a manual. Any way I can download a copy?

  10. I just found a basic set “D” on a fleamarket yesterday. I might scan and convert the manual to PDF at some stage.

  11. Hi i my name is jack. Suprisingly i have a kit still in pretty good condition and i was just searching for a instruction manual.
    Looks like i won`t find one.

  12. Hi Jon,
    thanks for the link. Is it possible to get the images in .EXE or .ZIP files? The reason i am asking this is because i have dial-up internet so i can`t be online all the time. I also went to the gallery site and got a few pictures but the only problem is trying to read the symbles and the numbers.

    Thanks again, Jack

  13. I have the Electronic Snap Kits 750 set, which includes a CD and cable so the PC can be used as an oscilloscope. I’m going to try to help my twelve-year-old grandson get started doing something besides WOW (World of Warcraft). I’ve made a list of DIY electronics sites, including Makezine, of course.

    Any suggestions as to where online there might be other youngsters who are interested in tinkering with electronics? I’m not exactly a peer 🙂


  14. Sounds like a cool kit Melody! Glad to hear you are trying to get your grandson into projects as well.

    First, if he’s showing any interest in it, I’d highly recommend a subscription to Make magazine. It’s not cheap, but it’s very high quality and has few ads.

    I have a few of my favorite electronics resources listed in this article.

    It may be of some help, but I would say you only need a couple good projects rather than a lot of OK ones. Start simple and work your way up.

    Hope this helps.

  15. Please qote or listed the price of this item Assorted Blocks, Test Lead,Test Lead in Assorted, Assorted Test Tube Caps,

  16. Lectron blocks are still available from in Germany. You can email the company at and write your email in German. If you need help translating, go to but be careful about plugging in English words that have multiple meanings. Always use the back translation feature to ensure that your correspondence makes sense. Then order as many Lectron kits and extra blocks as you possibly can, and enjoy. Cheers!

  17. I recently purchased one of these toys at a thrift store. It appears to be unused. All of the print is still on the blocks, and the wires are still bound with twist ties. All of the parts and the manual are there and appear to be in original condition. I have wanted to play with it since I got it, but have refrained in order to find out its value first. I am dismayed though to hear that they no longer make the toy or anything like it since i intended to replace it with something comparable if I sold it. Anyhow, if someone is interested in buying the set, I will consider offers. I also have a vintage Galoob RC Porsche, 60’s or 70’s, that also appears to be untouched and that I would also be interested in selling. If you are interested contact me at

  18. Clearly I did not read the above comments before I commented on the lack of a modern alternative – glad to hear they still give kids some credit for their ability to learn advanced concepts.

  19. My dad dave me a set of Bloc-Tronics when I was a kid and I still have them to this day. Yesterday, my ten year old son found them and was asking about what they were and we took them out of the packages and put togethor some simple projects. I was amazed by there condtion and that each component still worked has intended. I even put together experiment # 96 and was able to listen to the radio broadcast of the Giants and Eagles football game. I wish that toy producers would provide more projects such has Bloc-Tronics. It was exciting to see my son actually learn something from a toy.

  20. I found an unopened box last week at my local thrift store. How do I know which set mine is? Haven´t opened it yet but I guess that it should say somewhere on the box?

    // Tobias

  21. Somehow you missed the Bloc-Tronic kit on my site when writing your article! A friend of mine found this kit at a garage sale about 10 years ago and gave it to me. I’ve never done anything with it as I lacked the manual and some of the pieces seemed to be from other kits. So thank you so much for uploading the manual, maybe now I can make some sense of it.

  22. I was given the Advanced ‘AA’ Robot radio kit with the expansion set and manual. All in great condition…figured I’d save it for my kids…

  23. I was given a used Bloc-tronic kit as a kid in the ’80s. It wasn’t complete, so I was never able to make much with it…which was rather crushing at the time. I’ve always remembered it.

  24. PS- Okay, it’s still crushing. I don’t suppose anyone has a complete kit for sale? I would still really love to have one. I’ve read a few posts where people have said they’ve found unopened ones at yard sales for $10. That rather makes me want to cry.

  25. I bought this kit a few years ago at a market. I don’t have the original packing, just a wooden box with all the blocks and the manual.
    I really like the idea of having a set of blocks with logic gates :o)

  26. Jeez, I had a D kit when I was groing up.
    I lett a window op on my room during a rain session and it got destroyed. I was shattered.
    Just told my 8 year ld son of this toy and here I am.
    I’m of looking for a similar set for him.

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