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 »
Science Live is amazing!
He has Tetris in the background.
This is so cool! Never heard of this before!
Best episode so far love it keep it up!
this video was on my birthday. really funny but anyways i love science live go Dr R.
I love circuits, and this episode!
Let’s go , time for science live!
I watched the relay.
Tobias is so funny
What are some examples of the right solution that will bond for DNA?
I made a switch relay for my Science fair project. It is interesting to watch the Acellus video after learning about this in my old school.
This lesson was amazing I got to learn about relays and their importance and what they are essential for.
Learned so much new stuff watching Science Live!!
Dr R you’re awesome
My grandpa used wd-40 for everything! lol
R51 was so funny in this episode of science live.
Wow never knew all that about WD40 and I’ve been around and used it most my life
I love watching science live, thanks for bringing us another awesome episode!
R51 WAS SO FUNNY
this was the best episode it was funny
These science live videos are so interesting!
I have actually used WD 40 before
R51 is the best
R51 was my favorite part of this episode.
I loved learning how WD40 was developed!
It’s so interesting how much of technology can be created and expanded forming from one invention. I wonder how much different our reality would be if the first version of this (electromagnetic switch) was thought up even just ten years earlier or later.
I’m a little late to the party, but this one was fun!
I love r51
210 light years away is crazy!and to be able to see a gas like helium
R51 is so funny in this science live episode
its crazy seeing how much information about us is contained in one cell.
I never knew WD-40 had so many uses!
I did not know that WD40 was used on rockets to keep water off.
It’s amazing how many technological advancements we can make by looking at ourselves or other living beings
R 51 is one of my favorite things about science live lol
This science live was very educational I had no idea about relays and their uses.
My family uses WD-40 so much, squeaky things everywhere, it does the job though!
Hey from roanoke Virginia
R51 is so funny! a very interresting video! thank you Dr.B!
Hey from Virginia
I actually didn’t know that you could create giant radio waves with just a tiny spark! I might try this! I’ll see if I have the supplies. I love science, so this will be fun to do. I love Science L!VE so much!!!!!!!!!!!!!
This was so entertaining. My grandma joined me for this one haha.
hello from texas this is cool if we did not have curcits we would not have internet
R51 is so funny
It was interesting to see how a relay works and why such a simple idea is so important in circuits.
SCIENCE LIVE IS THE BEST
I use WD40 all the time on my bikes, i never knew thats what its name was.
Wow WD40 was never pattened! That’s crazy and it was originally made for NASA
I absolutely loved this Science Live!
R51 is hilarious
Loved this episode! Always a privilege to watch.
R51 is so funny in this one😂
This is so cool! I can’t wait to see the graduation and maybe meet my peers. I hope I can go.
I can’t wait to learn about vacuum tubes.
How many times should you try before you give up?
Hey from Missouri! Such a fun episode, thank you for all the detail put into these!
this site has help me so much before i was on this i was failing but now i’m not
This video was one of my favorites!!!
r-51 is hilarious.
Dr John’s Electronics class sounds very exiting!!!
This was cool becuase I like to build circuits with my science sets. Thanks Dr. B.
R51 is so hilarious. It makes it extra fun watching these episodes. My dad’s favorite “tool” is WD40. Lol.
SCIENCE L!VE IS AMAZZZZZING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
This episode was very interesting and I liked it!!
Always love the effort put into these episodes!
WD-40 on top. Perfect for everything, squeaky door hinges, rusted metal, jammed gears, cleaning. can go wrong with it.
This has truly been one of my favorite episodes so far.
radio waves are so interesting
wd40 is so cool.
this was a great episode about the relays I enjoyed it
I love watching these thank you!
DNA is so cool
It was so fun to watch how a tiny spark can ring a bell
R51 is actually so funny!
Thank you for the live this week!
When did you know you wanted to do science?
I love R51
Science is awesome!
Electricity is hard for me to inderstand
Science is so interesting!!
R51 Was Hilarious this episode
This is my favorite episode!
The relay was so cool!
I like how they invent the light.
I am starting to like science
i like the experiment that got done.
these videos are so interesting.
I enjoy watching science live! Wd-40 is very useful.
my big brother just finished learning about how the relay works in his electrician course and told me all about it.
I learned so much this podcast! Thank you.
R51 was hilarious.
I love science live, the episodes are so interesting!!
How is wd 40 made?
R51 always provides entertainment lol
Loved the live watched it with my brother
R51 was so so funny I can’t wait to see more.
R-51 always finds a way to do something wrong!
This looks awesome my favorite part was about the telescope and r51 is always funny!
That’s actually so cool behind the story on how WD*40 became to be, because I am always hearing how a scientist invention goes popular, or just on the shelf to buy, but I never hear the real back story.. I’m happy I heard this one, and it was actually interesting! I use this all the time with my dad when we are working in the garage. That’s so cool!
Go science live! Today was my bday…..this was a good gift
Relays are really cool.
I wonder if someone could use a special type of space in space ships for oxygen, sorry for making two of these.
R51 is hilarious
Never give up. Love science
Mr. Billings, really breaks down the science behind the control of circuits.
Thank you for sharing all this great information with us!
The like the information of circuit positions.
I didn’t know that WD-40 was important for rockets.
This is probably my favorite video yet
Really fun video! R51 so funny!!
I’ve never used WD-40 on other stuff than rust before, interesting alternative uses.
Sometime you guys should do a history live
Why are we talking about the relay?
R51 is so funny.
Very good and interesting video! :3
Go Science Live!! Dr R is so great
wow w2-40 is awsome do uou think you could use it with a car
R51 is so funny
He is.
R51 was so funny this episode.
This has truly been one of my favorite episodes so far.
These lives are always interesting and teach so much! I never knew most of these things
Dr.B made it look so fun and I’m going to go home and try it out
Yes he is everyone he always has been amazing isn’t he so so so so so so so so so so so so so so so amazing
I love watching these Science Live it is so much fun !!!!❤️😇❤️🔥
I never knew WD40 was kinda interesting
“another fine product…” (was their only product) lmao
so what if im using wd-40 on my legoes
I didn’t know you could create radio waves with a spark.
Relays are cool!
There are
I love science live!
Thank you for this Dr. B!!
r51 is halarious
i used WD-40 to get a coffee stain out of my table
R51 is so funny
It’s a good lesson to never give up, even if it takes 100 tries.
I use W2-40 on my bicycle!
Who knew WD40 could be that useful
DNA is very intresting, I would like to learn more
This episode was AMAZING!!!!!!
R51 is really funny
I loved R51
Watching from Chicago thank you for the wonderful episode.
What was the process of originally inventing a circuit relay?
It was interesting to learn about Wd40. my dad uses it sometimes in the garage.
There’s always something new I learn every science live!!!
R51 needs to start watchin what he says lol
R51 is so funny, he needs to be more careful!
Thank you for sharing all this great information with us!
wow interesting
loved this
I love learing about circuits and how to make them,
WD40 has so many uses! Who would have guessed!
Wow, the relay was so cool!
Poor R51, he got electrocuted!
I’ve only ever used WD40 on rust and things like that. I never really thought that much about it until this video.
same, i used it on my dirtbike chain haha
We made a circuit relay at home it was so cool
Sorry that you got shocked R-51!!!!!😭😭🥺
R 51 is soooo funny
love drb he is my fav
I never knew the history behind wd-40 until now
Hello from NC!
Here from Tennessee. I love learning
I never knew how radios work but now I do! Thanks DrB.
What are more ways vacuum tubes can be used?
I didn’t know WD40 is used for so many things!
I’m getting caught back up from Christmas break! Happy New Year everyone! I love learning about new things on Science Live!
Happy New Year! R51 is so funny
Science is the best
Science live is so interesting
I like the Thomas Edison quote, “I never did a days work in my life, it was all fun”.
Using DNA for storage is amazing and should be used!
I love the way WD-40 smells
Happy New Years from Nevada! It feels great to be back
WD-40 has so many uses but I never thought about how many and the amount of cans sold everyday!!!
Do twins have the same DNA?
My dad is a mechanic so WD40 is something I have always been told is a wonder tool.
My mom was so surprised when they said what WD 40 stood for.
WD-40 is a cool thing and used for so much stuff. I’ve seen my dad use it on cars and rusty things, we use it on my bike chain, I have even seen my mom use it to get ink out of the dryer, and crayon off the walls! It’s a really cool chemical that can be used for a lot of things, but it was cool to see what else it could be used for too!