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 »



R51 is funny
This is so interesting.
You’re the best Dr.B
My mom cannot make it to acelles world.
But I really want to come.
Is there an acellus world in charlotte nc?
I love R51!
Oh boy, I hope I can come to Acellus world one day!
I laugh at myself all the time, it does make failing easier lol
I didn’t know that WD-40 stands for water displacement fluid
I never knew WD40 had so many uses.
This was really cool, I liked it a lot
I like how funny this episode is
It is very interesting to see a very important tool in technology in action and how it works.
R51 is always so funny, I loved this episode!
Science live is mind blowing
Was cool to learn about the different ways to put wd40 to use
Amazing, that’s the only word to describe it.
Dr R is so great love this live.
It’s amazing how many tries it takes sometime to get the right formula for something to be successful and how sometimes you find out your invention has more than one use.
It was so cool learning how clocks actually work, I loved this episode!
this episode was so interesting
I hope1 R 51 is Ok
R51 is funny
The Relay he invented is so interesting and creative.
I watched this with my mom and sister and we learned alot
R51 is too funny.
This episode was fantastic and so informative. Dr.B really makes learning fun!
This was such a good live! Love R-51!!
Science live videos are so cool!!!
This episode was amazing!
Radio waves can be created with a spark?
I look forward to these!
I have always been fascinated by electricity and wires.
Love R51!
I did this in robotics for something in 4th grade, we had to test the electricity from batteries to a circuit to see if it could power a homemade oven while also using the sun with solar panels. It was super neat.
Dr. B makes this whole thing way more interesting!
It is very interesting that the bases of complicated technology is something that everyone could make.
Relays are amazing. And how it helps us with so many things.
Relays are my favorite please make more like this!
Is this something I can do safely at home?
can’t wait to create my own radio waves
Definitely one of the best episode yet!!
They relay technology is heavily growing
thank you for teaching me this!!