EEVblog #1135 - Science Fair 200-in-1 with Sagan

[EEVblog]

Sagan builds a rain detector circuit with Dave's original Science Fair Tandy / Radio Shack 200-in-1 electronics projects kit from the 1980's, and testing it using Dave's first multimeter!

[NiHaoMike]

That's very nostalgic since I had that kit and that style of wire stripper when I was about 10 years old! (My first multimeter was digital, though.)

Now I wonder for the first 23 circuits, has someone reverse engineered the schematics? I recall some of those were quite complex and were used to show off what the kit was capable of doing.

[JustMeHere]

UFO

[wilfred]

Would a kid without  anyone around interested in electronics choose such a toy these days? Or are they sold to nostalgic greybeards  buying them as gifts.
Who here had such a kit as a child and choose it entirely themselves and had no adult help?

[NiHaoMike]

Would a kid without  anyone around interested in electronics choose such a toy these days? Or are they sold to nostalgic greybeards  buying them as gifts.
Who here had such a kit as a child and choose it entirely themselves and had no adult help?

Probably a good choice for those who don't think an Arduino is a good way to start learning electronics. When I started electronics, my parents only helped me in the beginning and when buying supplies. At home, they rarely spent much time with me on that. Apart from electronics and other science experimentation, reading electronics and science books was how I spent most of my spare time back then.

I would like to see the use of FPGAs for learning about digital logic, but those are difficult enough for adults. I remember when my dad installed LabVIEW on the family computer and I had a lot of fun playing with it. I even used it for doing homework a few times...

[JustMeHere]

The newest version of this isn't horrible and lends itself well to Arduino.   There is a back powering issue with it though.  The batteries end up being connected backwards when the switch it off.

[SilverSolder]

Who here had such a kit as a child and choose it entirely themselves and had no adult help?

I did...  Parents had zero interest in technology.

If only Youtube had existed back then...

[NiHaoMike]

The newest version of this isn't horrible and lends itself well to Arduino.   There is a back powering issue with it though.  The batteries end up being connected backwards when the switch it off.

Can you explain how they managed to mess up the switch?

[floobydust]

This cartoon saved me as a kid, helped me to make sense of the parts I was wiring in my Science-Fair 100-in-one kit. Otherwise I would have ditched electronics.

[jancumps]

This cartoon saved me as a kid, helped me to make sense of the parts I was wiring in my Science-Fair 100-in-one kit. Otherwise I would have ditched electronics.

I had that one <3

[Tandy]

A copy of the manual can be downloaded from https://www.tandyonline.com/doc/28/28-249_User_Manual.pdf

[D. Head]

Do they have also Top Craft in Australia?

[fireant01]

To Dave and all fathers or mothers: I found this blog to be wonderfully exciting, watching a seven year old brain absorb technical material as Sagan does. As a father of two sons who retired from Texas Instruments here in Dallas, I can directly relate to this. Sagan is so fortunate to have a parent who can devote his knowledge and energy to his development. I raised two sons, however my working hours at TI in the Linear Products division were working 12 hour days and that hindered my ability to be able to focus on both sons. My boys however saw me working on equipment in electronics at home, and they learned much in observation such as soldering, troubleshooting to a faulty component, etc. One son went on to receive multiple degrees in Virus migration and now works for a well known big pharma company. The other son went into the Navy and now works in building maintenance of an 80 unit apartment unit repairing A/C, wiring, plumbing, etc.  The older son "the brain with the degrees" recently repaired his flat screen TV by replacing bad capacitors in the power supply. YouTube works wonders in teaching. Both sons have successful careers. The point of all this is that Sagan may go on to work in electronics later in life, or possibly not. But the knowledge he receives early in life with Dad will certainly add greatly to whatever his choices may become....Great work there Dad!!!

[MrMobodies]

I use to have one of those but it was an 130 in 1 kit. In the book it had diagram for some crystal radio where it powered from the earth such a radiator but it only sometimes worked. I wasn't careful and I ended up blowing the components. I  found a wooden one from a bootsale some months ago and I yet to experiment with it.

[rrinker]

This cartoon saved me as a kid, helped me to make sense of the parts I was wiring in my Science-Fair 100-in-one kit. Otherwise I would have ditched electronics.

 Oh wow, I had a 100-in-one but I forgot about those cartoons. I can't imagine how much I learned from things like that. I started with the 25-in-one, which had each component on a little plastic block with spring terminals at each corner. You connected the blocks with plastic clips and then there were thee stamped sheet metal L shaped bits you put on the spring terminals to provide the electrical connections, so creating your own circuits after doing all the ones in the manual was a bit like doing a puzzle as much as it was about electronics - though I recall there was one piece that was like a through connector - the top two terminals were connected together and the bottom two terminals were connected together. Then I moved up to the 100-in-one, which I got a LOT of use out of. Eventually I had a 150-in-one, but I'm not sure I even built all the examples - I do remember that I started cannibalizing components for other projects. Sadly, I don't know what ever happened to any of them.

[floobydust]

This wins the award for doing the most with one transistor IMHO. Wireless burglar alarm - AM transmitter and CdS light sensor.
Anyone miss the 2SB56? It was everywhere in the 1970's. edit: this circuit used the 2SCxx on the thick-film, probably 2SB56 couldn't do RF.
I got sentimental and bought the 100-in-one from eBay.

[JustMeHere]

The newest version of this isn't horrible and lends itself well to Arduino.   There is a back powering issue with it though.  The batteries end up being connected backwards when the switch it off.

Can you explain how they managed to mess up the switch?

Maybe my description is a bit wrong, the + rail is always powered. 

[nctnico]

Sagan is adorable. Makes me feel sad my kids are nearly full grown men already.