Thursday, September 8, 2011

Arcade Push Button Light Switch Redux

I got a lot of feedback on my post from a couple days ago about making an Arcade Push Button Light Switch.  Mostly that this task could be easily accomplished with a single DPDT 110VAC relay.  While this true, the original post was really about using what I had on hand at the moment to remake something I saw online.

Never the less, while I was at Grainger this morning picking up supplies for another project I also grabbed a DPDT relay, part no. LY2-AC110/120, to make another version of the arcade button light switch.  This is how I would make the switch if I was going to be purchasing parts for it.

Here is a schematic.  This sort of design has been around for ages.  I guess people used to use relays for all kinds of control applications and called it Relay Logic

* Update *

A few people have asked for more pictures of what wires go where.  Unfortunately, I do not have any photographs that would be useful.  I did draw the picture below, though and I know of at least one person that built this switch based on it.  If you are unfamiliar with working with 120v household wiring be sure to ask someone who is in the know for some help.  Getting a shock from 120vac is unpleasant. 

Below is a picture of the microswitches in the arcade pushbuttons.  As you can see they are more than capable of switching the voltage and current required for this design.

So, wire it all up, apply some hot glue and drink some coffee.

And then take an action video.  I am switching my frequency counter in this video.  It is kind of handy anyway as the power switch for the counter is on the back of the unit.  I don't always use my frequency counter, but when I do, it's a pain to turn it on.  Well, not anymore.

Tuesday, September 6, 2011

Arcade Pushbutton Light Switch

UPDATE:  If you would like to see different circuit design, have a look at version 2.

I was poking around the internets on Labor day when I came across this.  It is a wall switch intended to replace a boring old toggle switch in your arcade room.  My single arcade machine does not warrant its own room, but I do like the idea of an arcade button light switch.  So, in an effort to get up and do something I made this arcade button switch for switching an extension cord.  I have it plugged into the magnifier with fluorescent lamp on my electronics bench.

Since it was a holiday, I wanted to use only parts I had on hand so that I could finish this project the same day.  Fortunately, I have a pretty large selection of bits that included arcade buttons.  Sadly, I had no triacs, though and settled for a relay instead. 

There are quite a few ways that you could make a set/reset flipflop circuit for this purpose.  I settled on a 555 timer setup with relay.  The flipflop could have just as easily been two NPN transistors, but I felt like reminiscing with the venerable 555 timer

Download the schematic here if you like...

I very slowly drilled two holes in a cover plate.

Circuit assembly began with the relay I had on hand.  I soldered some leads to the normally open contacts on the relay and put heatshrink on the solder joints.  The unused, normally closed, pin on the relay was snipped off flush and insulated with a dab of hot glue.  Otherwise, this pin would have been an exposed hot leg of 110VAC.  Not a huge deal as everything is inside a plastic box, but it is a good idea to do.

Circuit assembly continued on a piece of perf board and was hot glued to the top of the relay which, in turn, was hot glued betwixt the arcade push buttons.

In the picture below, you can see where the hot lead of the extension cord is interrupted by the normally open contacts on the relay.  You can also see a knot tied into the extension cord in the top left of the picture as strain relief. 

Below you can see everything fits into the box nicely.  What isn't too apparent is a pair of black wires coming out of the box too.  I chose to use a wall wart transformer to power my circuit instead of the 110VAC coming into the box as this is just a bench top installation and not an, in the wall, permanent fixture.

Here is a video of the switch in action.  You can see the camera adjusting it's auto white balance as the lamp I have the switch plugged into is turning on and off.

This project was a fun way to spend the afternoon.  It certainly adds some geek cred to my electronics bench.  I think I am more interested in a monostable 555 circuit attached to the relay output, however.  That way, I could turn things on for a period of time and have them turn off automatically, instead of returning a day or two later to find out I left my soldering station on again.