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 »



Wow, I didn’t know. DNA could be like this.
R51 is so funny! 🤣
One of my favorite R51 appearances, always the highlight of the episode!
I’ve only ever used WD40 on rust and things like that. I never really thought that much about it until this video.
I never knew that WD-40 was sold that much!
Really interesting and entertaining episode.
Science lice is definitely a highlight of my week! Learning about such cool things like, WD-40 or DNA is always so fun.
Wow I didn’t know DNA could be used like this.
I never realized how important wd 40 was. It does have a lot of uses!
I am learning so much from science live, I really enjoy it!! Thank you for breaking it down and making it easy to learn.
Gotta love R51!
I never knew just how much WD-40 was sold everyday. That’s a lot of cans!!!
science live is the best !!!
What makes a circuit close and open.
I want to learn sign language!
I do too!!!!!! ☺️
I love to watch Science Live
I love Acellus Science Live!!
Everything is well explained and i never knew about WD40!
I love Science live!
Why do we use a relay in an electric circuit?
I never knew WD-40 means water displacement 40th formula. My family use WD-40 to make the doors stop squeaking in our house.
Thank you for not only sharing but teaching such great knowledge.
I didn’t really understand petabites till now
I love learning about electricity!
I love these and I think that it so cool that they do this for us❤️❤️❤️
We really enjoyed watching this, thank you for all you do Dr. Billings! Never knew much about circuits.
One of the best ones
Great Episode about relays.
I always thought WD40 was used for unsticking stuff!! I didn’t know there were OVER 2000+ certified uses!! Incredible! Also R-51 loves to claim everything for himself lol
The ending. Of the lives are My favorit
LOVE IT😍
I didn’t know that about WD40! LOVE SCIENCE LIVEEEE😁
I am amazed that I learned how WD40 was created. My mom used that stuff on our outdoor patio swing.
Levi here, love these episodes. DrB is so meaningful behind each science based idea.
How many circuits can you put together
i really enjoy the live labs. I learn so much from these cool videos.
I like watching the weekly science live. It is so cool to learn new things that I never knew.
The story of how WD-40 was created is hilarious! It is very interesting to learn about the different inventions that were made and how they were made.
I enjoyed learning about DNA and it’s ability to store information. Science is so amazing!
Every Science live I watch teaches me something new.
WD40 is so great that even NASA uses it of course.
Space IS SO COOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
My Dad knew the history of WD40 but my mom didn’t and now she said she is going to use it to clean stuff.
This was very well explained.
I actually did not know that about WD40, Thats crazy,
Wow the in person Acellus stuff looks so fun. Whenever I graduate, I probably wouldn’t be able to come because Kansas city is very far away from here, but I wish I could 🙁
Very cool story about the WD 40. Also loved the explaination on how the relay works with electricity and circuits. Thank you for teaching us.
I enjoyed this one. Learning about the foundational building blocks and mechanics of the electronics we use everyday is enlightening.
I like the Science live videos!
I LOVE SCIENCE LIVE
Another fascinating video. and a lot of stuff I likely would have never learned otherwise. Thank you for putting this program up for everyone to watch!
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!
Me and my dad love electronics we have all kinds of gadgets
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?
Hello my name is Ethan. go DrB go DrB!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
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.
Wd40 literally fixing everything
I like WD-40 it’s works like a genius when it comes to oil stains like grease, tar, lipstick and crayon like my little sister draws on walls and floors.
That’s so cool NASA uses WD40! I see my grandpa using this when the sliding door won’t close.
Science live episodes are so fun to watch and i love watching them
We should always stay optimistic and keep going, even when it gets difficult. Even great inventors struggles and felt things were impossible at times
I guess WD40 is a very popular spray, didn’t know NASA uses it!
I don’t think I ever would have thought to store data in DNA, wow!
This is one of my favorite science lives!
I think it’s really cool that WD40 stands for Water Displacement 40th Formula because it took them 40 times to get it correct! Ha!
WOW! Coherers are super cool! Thank you for teaching us Dr. Roger Billings!
R-51 is the best part!
I love every subject in acellus and there’s so much to learn and I’m excited to see whats next on acellus live!!
Learning about the WD40 and all it’s different uses was cool! I want to be a scientist
I would be very excited to meet my teachers in Kansas City at future events
I am so grateful that I get to learn new things!
Is R-51 ok?
I am so thankful for electronics.
I want to make a relay for a science project!
Electricity has always facinated me.
How do you measure the speed in a relay experiment
My Dad uses WD40 too. I like watching these Science Live videos.
i like how you turned on the light with the spoons. super cool!
I didn’t know all the things WD40 can be used for!
I am so thankful for these science live episodes I learn so much every single week! Thank you!
What is the difference between a relay and a transistor?
My dad used WD40 all the time
I love CIRCUITS SO MUCH!!! MORE VIDEOS ON IT PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
r – 51 you’re so silly and funny 🤣😂🤣😂🤣
Relays are so interesting. Thank you for explaining the process and the componets of the relay.
I never knew the company behind WD40’s name, just never really thought about the company name.
Dr Roger Billings makes it very easy to understand and walks us through it well every time, and i never knew there were that many uses for WD40.
Thank you so much Dr Billings and science live team!
I’m always happy to learn more from Science Live!
R-51 is so skilled he doesn’t even need coffee to focus even after a long day at Area-51.
I cant believe how long WD40 has been around and i just found out how it was invented!
Awesome video, thank you for teaching me new things
Hey from Oklahoma!
I love r-51
Can 4th Grade Students go to acellus world.
This was really cool to hear about. My dad is really into radios and I think he would love to hear about this!
Science live is so intriguing and fun!
im so grateful for this class!!
When I was younger, my mom got my sister and me a circuit set and figuring out switches and relays hands on was one our coolest toys. Learning how to control circuits for sound or lights or movement made sense when we could manipulate the pieces to learn what worked. This Science Live was next level! Thanks for taking the time to share scince with us.
Such a great episode! One of my favorites! I loved learning about DNA and cell storage and WD-40!!!
I never knew about WD40, that was so interesting!
Dr.Billings is so smart!
I love acellus!
The new acellus convention center looks very cool
Watching from Georgia!
To be honest only taking 40 tries to make WD40 is pretty impressive. You’d think it would take alot more trial and error.
The story behind how WD 40 was made is crazy.
I liked learning about the relay
I am so sorry I forgot to comment and just remembered!! I was gonna say I love science live so much! It’s taught me so much about science and I think I wanna pursue an education in it now!
I love watching science live! It is the best thing to watch!
I love all the ways there are to use WD40.
If I do ever invent something, I am going to NOT give up. I just won’t be able to. But, I’m not good at being creative and thinking of new ideas.
I like watching science live, it’s enjoyable!
Wow I didn’t know how useful WD40 is.
R51 is the best part of science live
I love WD40. Merry Christmas to everyone
i love learning about this
How reliable are cassette tapes compared to the memory of our phones and computers?
That is so cool about WD-40, my dad uses it all the time
R51 used organic grounding
Thank you so much for helping us learn new things!
I love watching this and learning new things thank you guys so much!!!!!!
WD40 is interesting. It has so many uses.
Helloo! sorry i forgot to watch it last week i was in vacation, but i love watching the science live videos!!
NASA uses wd40? I didn’t know that.
I love Science Live!!!
Science live is great
ohhh this might be my favorite episode! I love science live!
Learned many new things today! I love I’m able to!
I have a circuit set at home that this reminds me of.
My dad was in the navy and much like
NASA using WD40, my dad used duct tape to fix everything!
I have some snap circuits that have a relay.
I love how many uses there are for WD40! I wonder what other simple tricks NASA uses day to day.
I liked hearing about DNA I would love to learn more about it.
I LOVE SCIENCE L!VE!!!!!!!!!!!!
how long is dna stored for?
I wonder how much technology will advance in the future
My great grandpa said just about anything could be fixed with WD40 and some tie-wire.
the key stone holds the arch together
Checking in from CA!
its so amazing how things are invented/inspired by other creations! Science really is in everything
I love watching science live
I enjoy watching these videos.
I loved this lesson it was explained so well
This is the best part about school!