[Pete Mills] was browsing around online when he came across an arcade button light switch and immediately wanted one. He didn’t however want to pay the $35 asking price for the switch, so he decided to build it himself.
He says that his solitary arcade machine doesn’t warrant its own room, so he figured he would wire the switch up to an extension cord in his workshop instead. The switch was made with parts he had on hand, so seeing as he didn’t have any triacs, he opted to use a relay in its place. He thought about how he would construct a simple flip flop circuit for the switch, and settled on using a simple 555-based circuit instead of a pair of transistors.
The end result looks every bit as nice as the version available for sale online, and it works great as you can see in the video below. [Pete] has circuit schematics available on his site should you want to build your own, so if you do, let us know in the comments – we’d love to see different variations on the circuit design.
[youtube=http://www.youtube.com/watch?v=hJLqrkK4mJA&w=470]
“settled on using a simple 555-based circuit instead of a pair of transistors.”
Wait, what? He used a simple IC circuit instead of a pair of transistors? How is that simpler?
In the defense of HackaDay, they didn’t say an IC circuit was simplER than a pair of transistors, merely that it was simple (i.e. simpler than a more complex IC circuit).
^Hit the nail on the head. I’ll take blame for awkward wording, but I’m pretty sure most people picked up on what I was going for.
One would have to assume they meant “simple for a 555 circuit” not “simpler than the transistors”.
He just said simple, simpler.
I have done this before (as well as others) and I wanted to share my schematic, sorry, I just hand drew it right now.
http://www.mculabs.com/_media/ac-on-off.jpg
Won’t the AC on the input side of that relay in that schematic cause the coil to “repel” the contactor away and break it’s own circuit? Or are there relays that can take an AC input current?
Hi Mike,
This is certainly a better way to do things. The original design was done using what I had on hand. I made a version 2, using the single relay design after buying a relay for this purpose.
http://petemills.blogspot.com/2011/09/arcade-push-button-light-switch-redux.html
um why do you need a transistor or a 555 there is a normaly closed side to thoose switches use on to power a double pull relay closed and use the second side of the relay to old itself closed through the normaly closed off button then simple push the off to break the loop
why must everything have so much more too it
if the switches can handle line voltage then you can do this with a single pull relay and make it even simpler
I agree with Mike Bradley
why do you need a transistor or a 555 there is a normaly closed side to thoose switches use on to power a double pull relay closed and use the second side of the relay to old itself closed through the normaly closed off button then simple push the off to break the loop
why must everything have so much more too it
if the switches can handle line voltage then you can do this with a single pull relay and make it even simpler
A single relay would have been fine, no need for an IC.
Still cool, just sayin’
WOW COOL! Makes me wish I could replace my switches in this appartment with something like that! I agree with the 555 is going overboard, but still those buttons are so cool! Green on, Red off. Never like the manual switches that are installed normally. Everyone throws out a little spark that you can see in the dark. I wish I owned a house. :(
Good job, Mike. That is the classic start-stop circuit used in PLC industrial controls ladder logic. Now all you need are pinball buttons with normally-closed and normally-open contacts, and a double-pole double-throw relay (DPDT).
And it only cost $50 in parts plus labor.
I think the point of doing it this way was to use parts he has on hand. Otherwise a 2pole 110vac coil relay and the two buttons would have been enough. Pretty nice though. It works and he did not have to get any more parts. Some times the shortest path between points is a curve. Think outside the box.
Now I agree with William, many a time, I make bigger projects out of simple ones, only because I hacked it together with on hand stuff. I only posted my schematic, because there was a request for it in the orgininal post.
According to the builder’s blog, the builder was using what the builder has on hand, and the builder chose to use the 555 because they wanted to.
I’m not quite sure why were are all up in arms over the use of a 555 timer when a simple relay would do. The really important thing to note is that there isn’t a microcontroller or heaven forbid an arduino where a simple relay would do.
No, this project really warranted a gumstix!
Good grief, a 555 to turn on a light bulb…
Please correct me if I am wrong, and I know you will!
The thing is that to use the two button and a relay approach/construct, you need two different types of buttons. One that is normally open and one that is normally closed. Also you would need to have them in the correct color if you didn’t want to to have the relay closed when the light was off. And you also need a relay with a flip flop contact (or what ever they are called when they have 3 pins on the contact). Personally I like it! I don’t care even if he used a PIC16C84 or an Arduino. We are talking about a one-off here (no pun intended). I really like that people are use what they have at hand in the spirits of hacking stuff together.
Hey… it’s easy… you can do the red button with another relay… and you don’t need the closed button!
Gotta give you point for creativity!
You are not wrong in your analysis, you just overlooked the fact that these buttons have three contacts, each.
One contact is common, one is NO, the third is NC. So, you essentially have four switches at your disposal. Two NO switches (one red, one green) and two NC switches (one red, one green).
NOTE: There are arcade buttons that are just momentary switches that are only NO, but that is not the kind he used in this project.
I just knew it :-) Thats why I like HAD. The collective mind is a great power. Thank you for correcting.
So there isn’t an easy way to make this with a relay? Otherwise i’d be all over this.
Yes this was posted by Pete up above:
http://petemills.blogspot.com/2011/09/arcade-push-button-light-switch-redux.html
Another handy use for this type of circuit is when someone mounts a power tool in a fixture to make an ersatz table tool. I’m thinking circular saw or router.
This is also a vital safety feature for all those gingerly style lathes.
In these cases you make the off switch easy to trigger (like say with your knee when you are being pulled into a rotating lathe by your tie) The on switch is recessed. Hard to turn on, and easy to turn off
I’m glad Pete published the 2nd AC relay version.