|Radio Shack 150-in-1 Science Fair
Electronic Project Kit
|RECOMMENDED PROJECTS, sorted by difficulty
sorted by: Difficulty Level / Semiconductors / Relay / Project #
"Digital" circuits grouped near bottom
This versatile kit -- produced and sold by Tandy / Radio Shack in the late 1970s -- came with a large booklet that provided minimal basic information about the components, and 150 pages of individual "experiment" circuits that could be constructed with this very substantial kit.
HOWEVER, the booklet was not organized to be a truly useful tutorial on electronics -- and the experiments were arranged in a very haphazard way -- starting the user with rather advanced projects and concepts, before introducing basic ones.
Further, some of the projects had little educational or practical value -- but rather seemed to simply be in the book so Radio Shack could say it had "150 projects."
This NEW list, below, is the result of a minor attempt to search through the huge booklet, and sift out the best experiments for beginners, and organize them (somewhat) into a more logical progression -- from easy-and-essential basics to advanced-and-complex topics.
I encourage you to study the booklet's first 8 pages, to better understand the components and some basics, first, before using them. And pay close attention to safety instructions.
For user success, in order of importance, I've prioritized those projects for which:
NOTE: Additional tips on using this kit, and exploring electronics, are shown below the bottom of this list.
|A=Advanced||*** transistor advanced||C=Communications|
|B=Basic||**** complex semiconductors||D=Digital basics||Useful TOOL for learning?
|34||Graphing a Variable Resistance||42||B||-|
|35||Resistors in Series & Parallel||43||B||-|
|36||Capacitor Charge & Discharge||44||B||-|
|39||Generation of Electrical Energy||47||B||-||a bit complex|
|131||Battery Voltmeter Tester||139||B||-||U|
|41||High DC Voltage Generator||49||B||R|
|20||Solar Light Meter||28||B||*||-|
|43||Diode Action or Diode Switching||51||B||*||-|
|84||Delay Switching Circuits||92||A||-|
|149||Radio Frequency Signal Generator (Tracer)||157||A||C||-||U||useful radio monitor|
|37||Capacitor as a Spark Suppressor||45||A||R|
|40||High Voltage Generator||48||A||R|
|81||Relay Latching Circuit||89||A||R|
|83||Relay Light Flasher||91||A||R|
|89||Momentary-ON Call Switch||97||A||C||R|
|97||Relay & Speaker Buzzer||105||A||C||R|
|22||Solar Cell & CdS Light Meter||30||A||*||-|
|108||Crystal Set Radio (Simple Diode Radio)||116||A||*||C||-|
|132||Audio Output Meter||140||A||*||-|
|133||Low-Frequency-Response Audio Level Meter||141||A||*||-|
|21||CdS Photo Cell Light Meter w/ Transistor Amp.||29||A||**||-|
|109||Transistor Diode-Junction Radio||117||A||**||C||-|
|111||One-Transistor Radio w/ Diode||119||A||**||C||-|
|143||Variable Audio Oscillator||151||A||**||C||-|
|147||Light Hum & Noise Detector||155||A||**||-|
|148||Audio Signal Tracer||157||A||**||C||-||U|
|61||Speaker-Microphone Transistor Amplifier||69||A||**||C||R|
|82||Supersensitive Relay or Sensitive Electronic Voltmeter||90||A||**||R||Caution: Could Damage Meter|
|47||Voltage Regulator Circuit||55||A||***||-|
|104||Single-Wire Communications System||112||A||***||C||-|
|105||Code Practice Oscillator w/ Tone Control||113||A||***||C||-||U|
|113||RF-Powered 1-Transistor 1-Diode Radio||121||A||***||C||-|
|115||Transistor Radio w/ RF Amplifier||123||A||***||C||-|
|116||Coin Battery Operated Radio||124||A||***||C||-|
|119||Wireless Code Transmitter||127||A||***||C||-|
|126||Aural Continuity Tester||134||A||***||-|
|140||Sine Wave Audio Oscillator||148||A||***||C||-|
|141||Low Distortion Sinewave Oscillator||149||A||***||C||-|
|80||Electronic Relay Switching||88||A||***||R|
|85||Transistor Delay Circuit Using RC Time Constant||93||A||***||R|
|96||High-Power Alarm Oscillator||104||A||***||C||R|
|64||Coin Battery & Audio Oscillator||72||A||****||C||-|
|65||Oscillator w/ Turn-OFF Delay||73||A||****||C||-|
|117||Two-Transistor Radio w/ Transformers||125||A||****||C||-||#108 + #111|
|30||7-Segment LED Digital Display||38||A||*||D||-|
|31||Basic LED Digital Display||39||A||*||D||-|
|44||Diode Circuit Function w/ Switch & LED Display||52||A||*||D||-|
|48||Logic 'AND' Circuit w/ Switches||56||A||D||-|
|49||Logic 'OR' Circuit w/ Switches||57||A||D||-|
|51||Logic 'NOR' Circuit||59||A||***||D||R|
|50||Logic 'NOR' Circuit||58||A||****||D||R|
|72||Light Controlled Switch w/ CdS Cell||80||A||****||R|
|73||Light Controlled Switch w/ Solar Cell||81||A||****||R|
Always be ready to disconnect power INSTANTLY.
Never leave a powered-up experiment unattended.
Have a pair gloves (preferably rubber) handy -- in case voltages get too high, or battery or circuit temperatures suddenly go blistering hot. (I've burnt my hands with simple AA batteries caught in a bad circuit).
Generally speaking, voltages above 28 volts can be fatal to people if the power source has enough capacity -- which most do. This is especially true for the high-voltage (110 volts or more) power from wall outlets, light sockets and extension cords.
Ignore macho claims of people who claim to have survived high-voltage contact. It happens, just like some folks survive car accidents; but that doesn't make it smart to try wrecking your car.
Many of these circuits may not work at all with weak batteries, let alone dead ones.
Long-life, good-quality, 1.5 volt alkaline batteries are the most effective batteries for this kit. (Do NOT try to recharge them; they can blow up if you do -- mine did.)
This kit, like most electronics of the 1970s, assumed your batteries were of the NON-rechargeable types -- common 1.5-volt batteries.
of these, combined, produce
(The small rectangular alkaline batteries produce 9.0 volts.)
By comparison, nearly all rechargeable batteries produce just 1.2-volts per cell.
only 2.4 volts,
which can make a significant difference in the behavior of some circuits.)
(Most small rectangular rechargeable batteries produce 7.2—7.4 volts; a few produce 8.4 volts.)
...since most of these circuits WILL work with just 2.4 volts (or 8.4 volts)...
Rechargeable batteries are the most expensive batteries for an initial purchase (especially since you must also buy a recharger), but they rapidly pay for themselves as you use them up, and then recharge them, then use them again, over and over.
ONE good set of rechargeables does the work of DOZENS of "cheaper" NON-rechargeables -- quickly saving you a ton of money, and lots of needless trips to the store. One of the most quickly-profitable investments anyone can make.
About RECHARGEABLE BATTERIES:
There are various types, but...
About battery RECHARGERS:
About BATTERY BRANDS:
Rechargeable AND non-rechargeable, based on my experience:
About battery CAPACITY:
a 1.0 Amp-hour ("1 Ah") battery
-- more often called a 1,000 milliAmp-hour ("1000mAh") battery
-- can, at best, supply
1 Amp of currrent for 1 hour.
or 1 milliAmp (1 one-thousandth of an Amp) for 1,000 hours.
or 2 milliAmps for 500 hours.
or 20 milliAmps for 50 hours.
or 200 milliAmps for 5 hours.
And so on.
While NON-rechargeable batteries aren't usually marked with their capacity, nearly all rechargeable batteries are marked with their capacity, in mAh -- telling you how much energy the battery can hold at full charge.
Typical values in AA-size batteries range from weak 50mAh batteries (sometimes installed in cheap solar yard lights) to powerful 2600mAh batteries (top-brand consumer rechargeables). Some industrial batteries are even higher.
Most rechargeable AA batteries, today, can store between 1100 and 2500 mAh. It's far better to spend the little extra to get the higher-capacity batteries. They do more, longer -- and seem to survive longer in heavy use and recharging -- before burning out altogether. (Yes, even rechargeables eventually weaken, and find it hard to fully recharge -- and finally quit permanently -- but only after you've gotten more than your money's worth out of them.)
Devices that produce heat or motion tend -- on average -- to consume more amps than devices that produce light or sound. (NOTE: Old-fashioned "incandescent" light bulbs -- which give off light as a by-product of heating a wire, like the red "lamp" in this kit -- consume about 2-10 times as much energy as modern LED bulbs, for the same amount of light.)
Be careful to really learn BASICS, FIRST, THOROUGHLY -- before leaping ahead into fancy stuff. Real ability and success in electronics depends upon this. Those who master the basics FIRST, are far more successful in the advanced stuff.
REALLY SPEND TIME with ONE PROJECT at a time -- reading the instructions fully before beginnning, checking out the components before putting them in the circuit, carefully note the outcomes, and reflect upon them, and consider alteratives and practical applications. Talk it over with someone. Let the lesson really soak in, and truly enrich your knowledge.
If you can afford it, buy one of each type ("analog" with a moving needle -- and "digital" with a digital display) -- they each have advantages and disadvantages. Combined, they're really handy.