The Relay
December 10, 2025 • EPISODE 290
How does a simple relay help us understand electricity and circuits? In this episode of Science LIVE, Roger Billings breaks down the science behind the relay—the clever electromagnetic switch that makes it possible to control circuits with precision. Learn how relays work, why they’re essential in everyday electronics, and how this simple idea became a building block for modern technology. A clear, hands-on look at one of engineering’s most important tools.

About DrB
Dr. Roger Billings is a visionary innovator whose work has touched the lives of millions of students and transformed the landscape of education. Widely known as “DrB” to the countless kids who benefit from his groundbreaking Acellus learning system, Dr. Billings has dedicated his life to advancing education through technology.
As part of DrB’s lifelong commitment to supporting education, Science LIVE was launched as a way to “give back” by mentoring students in conjunction with the Roger Billings Scholarship Program.
Read more about DrB »
About the Roger Billings Scholarship Program »



I enjoyed this video a lot and very well explained.
I never knew that NASA used WD40!!
This makes me want to tinker with my own electronics at home!
I really LOVE the science live.I hope you enjoy this too.
I actually did know that about WD40, my grandpa is a mechanic and builder. He works with tools and has skills that he passes down to me when he can!
Science Live is the best things I watch all week!!
Circuits are so interesting.
Thanks for the science live! love learning new things.
I never knew WD-40 means water displacement 40th formula. My family use WD-40 to make the doors stop squeaking in our house.
That was so cool!!!!
DR. Billings you are amazing!
i love how much science lives have taught me
The WD40 session was so interesting and shows you should never give up!
Thank you for science live! I learn something new every time I watch.
Will the graduation ceremonies be held in the conference center every year from now on?
Super interesting! WD-40 was originally developed in 1958 to prevent rust and corrosion in aerospace application but you can use it on so many things. Never knew this is how it started.
I like how Dr. Billings explains a simple relay because he breaks it down in a way that makes electricity and circuits easy to understand. He shows how a small current can control a larger one, which makes the whole concept click.
i didn’t know that about WD40
R-51 Have an electro shot! 😂😂😂😂😂
I love this science live! This video is so educational and I love watching/listening to them. They are so educational!
Wd40 works for so much stuff, my mom uses it to all the time.
I told my grandpa about wd40, and now he wants to give it to everyone as a gift.
I just got a circuit set for Christmas. It’s really awesome.
i would love to learn about WD-40
I am so grateful for the science lives!
I love science live!
I love watching science live! It is the best thing to watch!
Isn’t it risky not trademarking WD-40 with today’s technology? Couldn’t someone analyze it and figure out the formula?
What would happen to a circuit if there were no relays at all? Thanks
We love Dr. Billings
WD40 is a wide-range utility that can be used in science for multiple purposes.
No joke R51 drinking someone else’s drink. The exact same thing my 2 cats do.
The most surprising thing to me is that NASA uses WD40.
WD-40 is so versatile
My Dad was just talking about a relay in his truck. Too funny!
My dad always says you need 2 things in the house to help with repairs Duct tape and WD-40!
I’m learning but it’s fun. I love Acellus!
The relay is so important in electronics. I love STEM class.
I am enjoying learning new things from Science Live!
I’ve never heard about WD40 before so it was interesting to learn about. It’s also encouraging, it shows how you can try again even if you fail!
Thank you Dr. Billings for Science Live.
So grateful to be learning new things!
Loved this episode!
I love watching science live! It is the best thing to watch!
That’s funny that’s NASA uses WD40.
I love watching these! I learned a lot about NASA that i didn’t know before!
I actually did know that about WD40, my grandpa is a mechanic and builder. He works with tools and has skills that he passes down to me when he can!
Thank you Dr. Billings!
R51 used organic grounding😂
I actually did know that about WD40, my grandpa is a mechanic and builder. He works with tools and has skills that he passes down to me when he can!
it’s so crazy that nasa uses wd 40
How old do you have to be to graduate from Acellus?
You have to be 16 years old.
I enjoyed everything about this video and how each subject was explained.
To be honest only taking 40 tries to make WD40 is pretty impressive. You’d think it would take alot more trial and error.
This is amazing!
WD40 can be used for so many things
I liked seeing Acellus World and would love to go there someday! Also, I liked hearing about DNA being used for storage.
WD-40 has so many ways to use it. Im going to tell my mom all these ways