Science fair electromagnet suggestions

[Instock]

My kid is working on an electromagnet science fair project. Basically, he's going to wrap wire around stuff and see what works best. I don't want to the science part for him, but he needs help with the logistics, materials, and safety. We have no experience with this stuff.

What are some cool things that we should put in his hands? What should we use for a power source? Batteries? USB? 12V? How can we control the current? Indicator lamp? Wire nuts? I dunno. Not sure what questions to ask, but hit me with some stuff the a 10yo kid could impress his friends with. I can solder if I absolutely have to, but it'll be ugly!

 

[Bluejets]

Electromagnet, use a relay stripped down.

It won't lift much but will show the principle if the armature and spring are left intact.

 

[Instock]

Electromagnet, use a relay stripped down.

It won't lift much but will show the principle if the armature and spring are left intact.

Interesting idea. That could definitely be one of them.

How do we power it? I have a 12v, 3 amp power souce from a car radio store that closed. I also have a Bluetti solar generator battery that can give me 12v, 10 amps, as well as USB ports. My dad wants to donate a model train transformer and we can do it with AC? I have a power supply for jumping my car that has USB. Or just keep it simple with a lantern battery or some AA alkalines in a holder?

 

[Bluejets]

Simple battery is best for kids, safe, portable (if using AA cells in a battery case/holder). Voltage of relay to match close to battery. i.e. 4 AA (6v) is ok for 5 or 6v relay....plus it suits Vin to Adruino uC which I'm sure the kid would be more interested in for control of infinite number of devices.
Just don't be surprised if they leave you in their dust trail.

Word of warning...do not use 9v smoke alarm battery.....except in smoke alarm or maybe your multimeter....you have bought the kid a multimeter I take it. Plenty of videos on how to use basics and cheap as...just don' t go testing anything mains level....

 

[Delta Prime]

I bought this one for my little booger blasters.
Shop around. Use only as reference please...
If nothing else it'll give you a proper safe idea!

Amazon.com

 

[Bluejets]

Mmmm....ok...I'll bite...what are you referring to???

 

[Instock]

Mmmm....ok...I'll bite...what are you referring to???

What is what referring to?

 

[danadak]

Experiment with Electromagnetism Science Projects

Over 1,200 free science projects searchable by subject, difficulty, time, cost and materials. Browse the library or let us recommend a winning science project for you!

www.sciencebuddies.org

16 Shockingly Fun Electricity Experiments and Activities for Kids

Play dough circuits, LED magic wands, and more!

www.weareteachers.com

20 Engaging Activities To Teach Electromagnetism - Teaching Expertise

Are you teaching about the electromagnetic spectrum this year? Look no further than the activities below to find something engaging to get your class excited to learn! Electromagnetism is the interaction of electric currents or fields. With quirky crafts, hands-on experiments, and more, you’ll...

www.teachingexpertise.com

Regards, Dana.

 

[Instock]

I'd love to give them a way to watch the current, but my old Meyer says to not hook it up for more than 15 seconds. We already blew the fuse once. Could I use one of those clamp meters or....?

 

[danadak]

Most low cost Clamp meters current measurement good for AC, not DC current.
Check your meter manual.

Low costs ammeters :

ammeter digital - Buy ammeter digital with free shipping | Banggood Shopping

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www.banggood.com

Regards, Dana.

 

[Instock]

Yeah, it seems like only the most super-expensive meters have dc on the clamp.

I bought a little 10 amp analog meter, but I think the resistance of the meter itself is too much when my only load is a coil of wire?

 

[Instock]

It seems like I actually get more current by putting batteries in parallel than in series. I would have bet money that putting them in series would increase the voltage and thereby increase the current. It seems like putting them in series does increase the voltage, but that is countered by the increase in internal resistance. The total current doesn't change much. If, however, I put them parallel, the voltage stays the same while the effective internal resistance goes down. The current increases! At least that's my explanation so far. Thoughts?

 

[Delta Prime]

The total current doesn't change much. If, however, I put them parallel, the voltage stays the same while the effective internal resistance goes down

You were doing really good! Until effective internal resistance. I can see why but you can't think of the effective internal resistance like that, it's going to confuse the heck out of you.
When you combine two electrochemical cell's
you get what is called a battery.
Internal resistance of a battery is the electronic resistance plus the ionic resistance.
This is called " total effective resistance" of a battery.
The electronic resistance is dependent upon the alloys used for the positive & negative terminals.
Ionic resistance, is the resistance to current flow within the battery & this is dependent upon the chemistry of the battery, electrolyte conductivity, ion mobility & electrode surface area.
And all of this has to do with battery current capacity.The charge of a battery can only be seen (measured) when it's connected to a load & that is depended on battery chemistry, depth of discharge, drain rate & the age of the battery can impact internal resistance during discharge.

BU-302: Series and Parallel Battery Configurations

Read about serial and parallel battery configurations. Connecting battery cells gains higher voltages or achieves improved current loading.

batteryuniversity.com

 

[Martaine2005]

In series, the voltage adds up and parallel the current adds up.
Example: 2 x 12V batteries @ 100 Amps each wired in series = 24V @ 100 Amps.
2 x 12V @ 100 Amps each wired in parallel = 12V @ 200 Amps.
Read the link that @Delta Prime gave above.

Martin

 

[Bluejets]

Then throw in a load of 120 ohm.
On 12v = 100mA.
On 24v = 200mA.