• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Help with son's science project

Shniggysaurus

New Member
Hi everyone. I'm trying to help my son with his 7th grade science project. We are testing a model of a geothermal power plant. Basically we will use steam to spin a turbine connected to a motor to make electricity. We would like to connect the motor to some kind of charging circuit connected to an 18650 and then connect that to a USB port to charge a phone just to show a useful application. We can do whatever soldering we need to but I'm not sure of the pieces we will need to charge the battery and output via USB. Any help will be much appreciated.
 

Nigel Goodwin

Super Moderator
Most Helpful Member

alec_t

Well-Known Member
Most Helpful Member
Welcome to ETO!
A successful outcome will depend a lot on how much energy you can extract from the turbine. What size do you have in mind and what research have you done to establish the likely output?
 

audioguru

Well-Known Member
Most Helpful Member
An 18650 battery cell is Lithium. A lithium battery cell will explode and catch on fire if it is not charged correctly and you did not mention using a proper charging circuit. The voltage from an 18560 cell is too low (an average of 3.7V) to be USB 5V to charge a phone.

If your steam engine is the same as the one I had years ago then it will not have enough speed or power to drive a motor to make useful electricity.
A steam turbine sounds powerful. Please post a link to its datasheet.
 

DrG

Active Member
If your steam engine is the same as the one I had years ago then it will not have enough speed or power to drive a motor to make useful electricity.
Did yours look like this one?

120480

I love your posts audioguru , I really do, and I have read them for quite a while on several sites where I have seen them. You definitely know a great deal about audio (at least much more than I do, but I have absolutely learned a great deal from reading those posts), but you may possibly be the most curmudgeonly human on the planet...." you might as well tell the kid that it wont work and he is going to burn the school down and put his eye out" ;)

I'm telling ya, you could write a book titled "You think you're a curmudgeon??" and get kick backs from anti-anxiety and anti-depressant makers world-wide.
 

DrG

Active Member
Hi everyone. I'm trying to help my son with his 7th grade science project. We are testing a model of a geothermal power plant. Basically we will use steam to spin a turbine connected to a motor to make electricity. We would like to connect the motor to some kind of charging circuit connected to an 18650 and then connect that to a USB port to charge a phone just to show a useful application. We can do whatever soldering we need to but I'm not sure of the pieces we will need to charge the battery and output via USB. Any help will be much appreciated.
Having been a judge at my share of High School Science Fairs, let me first congratulate you on having a 7th grader (approximately the onset time of hormonal insanity) who does not have a project based on some perceived difference between genders or which type of music makes plants grow the best.

I take it that you “engine” is somewhere between this


and this.


Assuming also that you are familiar with the safety regulations at the school concerning projects, you want a nifty demonstration and one that can be understood and explained by the 7th grader (not you).

The battery charger is a bit problematic. On the one hand, it is compelling because one of the few things a 7th grader actually does understand is that their phone has to be charged. On the other hand, a charging circuit has a number of other considerations and, even in the best case, would probably take a while to actually charge a battery making an on-site demo difficult.

I would offer two suggestions.

First, while I am reasonably certain that the output of the generator can turn on a single LED, if it could turn on a string of them, they could be incorporated into a model house or model street lights. Then, and this is important, the 7th grader would have to explain how large and efficient the generator would have to be to get beyond the model and into the practical….you see where I am going?

The second would be to use the generator to power a BLE beacon that could transmit some environmental information or just an advertisement that it is on. The second part of the project is that the 7th grader would have to write the simple app that could tell when the engine was running. If it is a one other thing that 7th graders know, it is that they love their apps.

Ok, more seriously, what is it that the kid is going to demonstrate that he has learned more than say, ye old active volcano?
 

Pommie

Well-Known Member
Most Helpful Member
To get a steam turbine producing any power will require steam at fairly high pressure which may be deemed dangerous. A safer idea could be a water wheel run from a tap. It would need gearing up a fair bit to drive a motor at a good speed but should be doable.

Mike.
 

gophert

Well-Known Member
Most Helpful Member
Shniggysaurus
Tell your kid it wont work and he is going to burn the school down and put his eye out.
Don't play with lithium batteries. Show the work potential in a safer way - a light bulb (LED) and a light meter to show the intensity. Maybe a light meter app is available for your android or iPhone.

Also, your steam engine can't be a simple little sterling engine - you'll need something with force. Before you start, connect the wires of your motor to each other and try to spin the motor - you'll see it takes a lot more force than when the wires are not touching each other. Now you'll have a feel for the kind of turning force your steam engine will need to make any electric power.

Cheers.
 

be80be

Well-Known Member
You don't have to use steam Use air for the steam it be easy to tell someone for safety reasons you used air.
Add charging a phone is not that hard just takes time as pointed out.

steam is not to be played with you can burn the skin right off your hand and not know it happen till it's to late.
 

Latest threads

EE World Online Articles

Loading

 
Top