Vellman makes all kinds of kits. Unfortunately, their kits cost about $3 10-years ago and now all seem to be in the range of $10.
The link below is in the UK but all of the Vellman kits are easy to see. Not all are rewarding but just soldering practice gimmicks.
https://static.rapidonline.com/downloads/2020-edu/electronic-kits-components.pdf

Jameco near SFO airport carries some of them. The Vellman group website lists other US distributors and they are possibly available online. Finally, tell the company you're buying from that you want a volume discount on 100 kits and you might get it (even if you mix/match kits - the distributor may give you a discount). Note that there is a chip shortage so this year wasn't the best year to start this.

 

You are far over their heads and I used to teach HS Science. Getting them to understand and how to apply Ohm's Law maybe. I taught a "computer" class that had no computers until I found some old ones stacked in a closet. I had to check out each one and do a fresh install of the base OS and the application for them to learn how to use, which was MS Power Point. The only other task I had each one to do was make a working CAT 5 patch cable with the tools and components I supplied and test it in order for ME to build a LAN with 2 printers attached with LAN printer servers. Even that was like pulling teeth and I'm sure some of the cables were made by their buddies and not by them. A normal training course that would be used for adults to take in ten 2-hour sessions took them a semester to complete.

 

You are far over their heads and I used to teach HS Science. Getting them to understand and how to apply Ohm's Law maybe. I taught a "computer" class that had no computers until I found some old ones stacked in a closet. I had to check out each one and do a fresh install of the base OS and the application for them to learn how to use, which was MS Power Point. The only other task I had each one to do was make a working CAT 5 patch cable with the tools and components I supplied and test it in order for ME to build a LAN with 2 printers attached with LAN printer servers. Even that was like pulling teeth and I'm sure some of the cables were made by their buddies and not by them. A normal training course that would be used for adults to take in ten 2-hour sessions took them a semester to complete.

Just curious what you would have them do then?

 

Vellman makes all kinds of kits. Unfortunately, their kits cost about $3 10-years ago and now all seem to be in the range of $10.
The link below is in the UK but all of the Vellman kits are easy to see. Not all are rewarding but just soldering practice gimmicks.
https://static.rapidonline.com/downloads/2020-edu/electronic-kits-components.pdf

Jameco near SFO airport carries some of them. The Vellman group website lists other US distributors and they are possibly available online. Finally, tell the company you're buying from that you want a volume discount on 100 kits and you might get it (even if you mix/match kits - the distributor may give you a discount). Note that there is a chip shortage so this year wasn't the best year to start this.

The Christmas tree might be an option but I am not sure there is much thinking to it more than there is just the soldering portion of it.

 

Here is just brain storming. Hence there is no need to get anyone's knickers in a twist over this.

You can order parts from anywhere. You can go to one of the big 3, Digikey, Mouser, Newark. Or you can go to eBay or AliExpress.
I chose a middle ground in order to get some price estimates and went with a supplier in the U.S. who has a reputation at stake.

My off-the-cuff cost limit was $20 per student. So we're under budget at $12 at this point.

Project #1
I like some of the suggestions so far. Start off with a simple project that is easy to build. Hence a flashing LED.
You would need soldering stations that stay in school. Students get to take home their supplies for show & tell.
Basic supplies include 400-point solderless prototyping board and foamboard for final assembly and soldering practice.

Experiment #1, 2, 3
Objective: Learn and understand Ohm's Law
Equipment needed: Variable lab bench power supply, Digital Voltmeter & Ammeter,
Components needed: resistors, LED
Exercise #1: measure voltage and current and demonstrate Ohm's Law, I = V/R
Exercise #2: draw the I/V curve of 100Ω, 1000Ω resistor and an LED.
Exercise #3: demonstrate why you need a series resistor to drive an LED and what value resistor to use

To come next: Project #2 and exercises
Your ideas are welcome.

 

For the next projects, here are some ideas I am pondering:

Ring Counter using 4017
Joule Thief
Final Project: AM Radio

What are your thoughts?

 

Just curious what you would have them do then?

Good question since none of the General Science (8-9th grade) or Physics 12th grade) textbooks covered electricity. What I did do that got a lot of class interest was electrolysis of water into hydrogen and oxygen, anything that goes flash or bang gets their attention like igniting H2 or O2. For chemistry to demonstrate the energy in the chemical bond I would make small amounts of NI3 (nitrogen tri-iodide) which makes a nice bang when the bonds break. To demonstrate single reactions, I would take them out and let them mix a pile of zinc powder with flour of sulphur and ignite it with a piece of magnesium strip to get enough heat to initiate the reaction. Which produces a very smokey volcanic reaction (why outside after I set the building fire alarm off the first time) to get zinc sulfide. Demonstrating Sodium and H2O reactions are very popular but make sure the kids are downwind (or use a fume hood indoors, outdoors better) to avoid the sodium hydroxide fumes. For general science to demonstrate the density of gases I would take them out and had a large roll of black plastic tubing (~4' dia.x50' long). Tie one end and let them run around and fill the tube with air and tie the end off. Then let the sunlight heat the air and float it up into the sky, tie it off with string of course or it would continue to rise and become an aviation hazard. We made the front page of the local newspaper when one of their reporters spotted us and stopped to ask just what the heck were we doing? For equal and opposite reactions there were water filled and pumped with compressed air 2-liter bottle rockets. Anything along those lines where the FUN element is enough to get their attention and make them WANT to participate. I brought in a block and tackle and let the boys in the class compete against a single girl in a tug of war one day to demonstrate the force increase of multiple pulleys. One year the Biology textbook used was pretty much a botany book so every nice Wednesday I took the class outside to look for what we were studying in class. Maybe a very simple circuit with a battery, resistor and LED to demonstrate converting voltage into light and a multimeter to allow them to measure the battery voltage, voltage drop across the resistor and LED. Plus, have them measure the circuit current as a demonstration of Ohm's Law. Have them draw the circuit, assemble it and take the measurements. Anything much more complex than that... The idea is to do what THEY have fun doing as it causes their buy-in and enhances the lesson. It's also nice as a teacher to break up the routine a bit. KISS applies here!

EDIT: I'd stick to breadboards and avoid soldering...

 

I'd do something that doesn't go bang because it is far too much paperwork - especially if something goes wrong. No reason to lose a pension over your over-zealous creativity and motivation.

For example, a local teacher invited a relative to do some experiments for his high school class. The Nitrogen Tri-iodide was sprinkled in the classroom floor to surprise some students as they entered. It turned into a major investigation when some kid's new Nikes were stained purple with iodine with one of the pops. And one girl screamed and felt embarrassed - then tried to sue the school for her PTSD that the pops caused.

No teacher was ever blamed or risked losing their pension or seniority by doing average work. Sorry.

 

There are some things better left to the teacher to demonstrate but only after thoroughly explaining the chemistry behind it and what to expect. The kids loved "That poppy stuff". A little bit goes a long way and WHEN the filtrate becomes too dry simple air pressure will ignite it so caution is required. I've had it explode in my hand while bringing it from the lab to the classroom across the hall because it had dried for too long.

 

Off topic:
My high school chemistry teacher was a VSO (Voluntary Service Overseas) from the UK. He demonstrated the production of NI3 and left it drying on the floor. Then he dropped a bunsen burner gauze mat on to it. The loud explosion brought the head science teacher running in from the physics lab next door to investigate. He was not amused.

 

If you have kids soldering, you'll need a nurse ready with some burn ointment. Kids tend to do this, especially if they set the soldering iron down on a table and pick it up again.

You can tell these were all photoshopped because the user's screaming mouth and watering eyes were all corrected. Either that or the irons were not plugged in.

 

You're getting more ideas than you probably want.

Some students may benefit from seeing what happens to a nail when you wrap 20 or 50 turns of copper wire around it and connect it to a carbon-zinc battery. Pick up paperclips, deflect a compass needle then swap the polarity of the battery connection and show the other end of the compass needle being attracted. The patter could include references to audio speakers, iron ore separation, even the speakers inside their telephones.

Electricity became magic for me when my father brought home a D cell, a flashlight bulb and a short piece of insulated wire. Sometimes the simplest demonstration and trigger a child's imagination.

 

There are, possibly, competing goals here. You have constrained time and budget, as well as limited knowledge.

I think I would boil it down to this: investigate the early experiments in electricity before it was understood. The creation of batteries (Volta), the creation of motors and electromagnets (Faraday, et al), the mathematical characterization of Circuits (Ohm), and maybe some information about the ideas of Benjamin Franklin who was actually very important and respected for his work.

The experiments they did are generally easy to reproduce in a science class environment, it can be like rediscovering the material, and there are many, many resources for how to do these experiments.

Then, jump to the transistor and talk about the invention at Bell Labs, there is a lot of good human content there in addition to the technology. Simple circuits like a two-transistor relaxation oscillator provides a great opportunity to talk about circuits and the application of Ohm’s Law which is fundamental to practical circuits, and to the action of the components (transistors, resistors, capacitors, etc,)

There are excellent resources to get you up to speed, some of it also possibly helpful to the students. One rich and mostly authoritative source is the Cathy loves Physics and History YouTube series (linked above several times) on the discovery of electricity and the development of the technology. Since she is an historian as well as a physicist, it includes a ot of human interest which is a real attention keeper.

The other thing I strongly encourage should you try this route is the book Crystal Fire about the developem of the transistor. It accurately explains the technology but as with the YouTube series it includes the people and personalities and how they influenced the process—for good and bad.

Once you have the basic idea of circuits and Ohm’s Law you could spend some time relating these things to, say, wind and solar power showing the challenges of providing enough power through renewable resources. Possibly including Einstein and the photovoltaic effect.

You can’t teach everything, of course, but you can provide enough foundation that those interested will have a launching point to investigate further and those who don’t will at least know something about the physics and technology reducing the confusion about the nature of electricity and the electronics they use everyday.

 

I think I would boil it down to this: investigate the early experiments in electricity before it was understood. The creation of batteries (Volta), the creation of motors and electromagnets (Faraday, et al), the mathematical characterization of Circuits (Ohm), and maybe some information about the ideas of Benjamin Franklin who was actually very important and respected for his work.

Yeah, I think you can't go wrong explaining things in chronological order. There is a reason they happened in that order.

 

Thanks for all the input. I appreciate all of you that took time out to give me input. Many of you provided information that I did not consider and ideas that I did not consider. I may reach out to some of you individually when I finish kicking the can down the road. I feel as though I may have put the cart before the horse on this one. I know what I want to do but I also know that my budget is limited. I may be shooting too high in the way of what I want to do. I will take a few days to figure out what I want from the project that is more realistic for my level, the student's level, our time, and our budget.
Thank you again for your time!!