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A project log for Inspecting the 150 in 1 kit

Revisit a 1976 kit to determine if an old lion is smarter than a 9 year old lion.

lion-mclionheadlion mclionhead • 07/24/2026 at 00:07•0 Comments

It turned out there was but 1 manual from a 1976 electronic kit on the internets.

https://archive.org/details/science-fair-150-in-1-electronic-project-kit/page/n7/mode/2up

Sadly, nothing from the 80's was ever scanned in.  So the lion kingdom could at least peruse the 1976 version & see if age enlightened anything, if anything that didn't work 40 years ago could be fixed now.  The 80's version had an LED in addition to the incandescent lamp, a single TO-92 transistor, & a reed switch.  The 1976 version had a 7 segment display, BA302 audio amplifier, & a cadmium sulfide cell which the 80's version did not.  They used the 7 segment display as a bunch of loose LEDs instead of a numeric display.

Perusing the size of the WIRING SEQUENCE text, the gnarliest build in 1976 was project #2.  The 80's version started easy & got harder in the back.  Young lion never bothered with the most complicated builds.

The schematics weren't intended to be read.  They have ground on top & 9V on the bottom.  Fortunately, any schematic can now be fed into a model & summarized in natural language.  They used either the speaker or earplug as a microphone or a speaker, depending on the application.

What was once called a joule thief, during the green revolution.

Everything relied on a single transistor oscillator.  If that didn't work, the whole kit was cactus.  This one seemed to always use a transformer with the transistor to make a sustained tone.

Their basic single transistor oscillator used a transformer + transistor.

Young lion busted his balls on a siren of some form, but never got it to work.

The BOM is in the back.  They used a 2SB56 germaneium transistor for the audio oscillators & a 2SA52 transistor for the RF oscillators.

They had a lot of sound generators, sine wave generators, oscillators.  

Lion eyes started watering with the wheatstone bridge & the capacitance bridge. 

They had some AM transmitters & a bunch of amplified receivers which young lion didn't have.  The transistor radios were the most complicated projects.  They used the same variable transformer as the receiver to generate the carrier.

A lot of projects required stuff which didn't come with the kit, like a coin cell, neon lamp.

There were a lot of typos.  No spell checking or language models in 1976.

This kit had a lot of flip flop circuits which the lion kit did not.  Young lion really just cared about a radio & an LED blinker.

They had all the logic gates using transistors.  It would almost be a good reference if there were no language models.

They had some high voltage generators which were banned by the 80's.  They used a relay as an oscillator.

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