How to make a momentary latching switch

Description

A pair of momentary switches become a latching on/off switch as Harley expands on a previous video about remote controlling a shop vac. This is the first of several in a modular switching system to remote control shop equipment using the PowerSwitch Tail II.

The central part of this system is the PowerSwitch Tail. It contains an electronically controlled switch to turn things on an off. There are a large number of ways to control this. In this episode, we introduce a modular system to allow different types of switches to be used to control the shop vac (or any other type of appliance).

PowerSwitch Tail II (Amazon affiliate link)

How to easily make a low-voltage, remote shop vac switch

For a written transcript, go to House of Hacks: How to make a momentary latching switch

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at http://incompetech.com
Special effects: livingroom_light_switch by AlienXXX at http://freesound.com

Transcript

Last year I showed an easy way to remote control shop equipment using a PowerSwitch Tail, a couple batteries, a switch and some wire.

Today at the House of Hacks I’m going to show how I made a push-on/push-off switch that mimics the way a lot of shop equipment are controlled.

[Music]

Hi Makers, Builders and Do-it-yourselfers. Harley here.

Just a quick reminder, if you haven’t done so already, subscribe to the House of Hacks channel to get notified of future videos.

Last year I made a video responding to a comment by Rob about how I made the remote control switch on my central shop vac system.

In that video, I showed the core design element: the PowerSwitch Tail and how to use it with a simple battery operated switch.

Today i’m going to show a different way to control the same PowerSwitch Tail by eliminating the batteries and using a switch with two buttons: one to turn the tool on and one to turn it off.

This is similar to how many shop tools are controlled. It also has the additional feature of being able to be expanded upon in the future.

If you recall, the PowerSwitch Tail requires 3 to 12 volts DC applied to these two connectors to cause the tool to turn on.

Batteries are of course one source of power for this but they need to be replaced on occasion.
Since I didn’t want to deal with replacing batteries, in my application I decided to use a surplus wall wart style power supply. I had a bunch of these lying around and figured this would be a good application for one of them.

I plugged it into the same outlet I plug the PowerSwitch Tail into.

I connect the low voltage power supply to two connectors on an RJ-11 jack.

Then I connect the other two connectors on the RJ-11 jack to the two connectors on the PowerSwitch Tail.

This allows me to use a phone wire as an extension cord.

For the switch's end, I put another RJ-11 jack in a project box. This project box can now have any type of switch mechanism in it I want and provides a nice modular way to use different types of switches.

For example, I could put in a toggle switch just like I showed in the last video.

Simply wire the negative side of the power to the negative input on the PowerSwitch Tail and wire a switch between the positive side of the power and the positive input for the PowerSwitch Tail.

However, since we have power in the project box, we aren’t limited to just a simple mechanical switch.

We can build circuitry that controls the PowerSwitch Tail.

The first thing I’ve made is a simple latching switch.

Similar to the switches on many tools, like my drill press and my bandsaw, I press the green button to turn on my vacuum and push the red button to turn it off.

Inside the box is a simple flip flop.

A flip flop is a type of circuit with two inputs, called Set and Reset. It also has two outputs, called Q and bar Q, or also known as not Q. It’s just the inverse of Q.

The inputs receive momentary pulses.

If the pulse is on Set, then Q goes high and bar Q goes low.

If the pulse is on Reset, then Q goes low and bar Q goes high.

If we consider just one output, Q, we can see Set causes it to turn on and Reset causes it to turn off. It just flip flops between the two positions.

Flip flops can be made with a variety of different circuits ranging from discrete components to various types of integrated circuits.

I happened to have a Quad 2-Input NOR gate chip in my parts bin so I used that.

But I could just as easily have used NAND gates, a chip with a dedicated flip-flop circuit in it, or a couple of transistors and resistors.

Once I had the circuit built, all I had to do was put it in the box and wire it up.

The switches are wired with pull down resistors. This allows the inputs to be normally low and go high when the button is pressed.

The green button connects to the Set input. The red button connects to the Reset input.

The negative input to the PowerTail Switch goes to the negative power connector.

Since I’m switching the positive side of the power, I’m using a PNP transistor.

Its base connects to the flip-flops Q output.

The PowerSwitch Tail’s positive input goes to the transistor’s collector.

And finally, the transistor’s emitter connects to the positive power connector.

In this configuration, the transistor acts as the switch for the PowerSwitch Tail’s power.

When it’s all put together, pushing the green button turns on the appliance and pushing the red button turns it off.

Since this switch system is modular, I have plans to build other switches too.

The next one is a current sensing switch so the vacuum will automatically turn on when a tool is in use and will turn off, after a short time delay, when the tool is turned off.

I’d love to know in the comments below if the level of detail I presented here was too much, just right or too little.

If this is your first time here at House of Hacks: Welcome, I’m glad you’re here and would love to have you subscribe.

I believe everyone has a God-given creative spark.

Sometimes this manifests through making things with a technical or mechanical bent.

Through this channel I hope to inspire, educate and encourage these types of makers in their creative endeavors.

Usually this involves various physical media like wood, metal, photography, electronics, like in this video, and other similar materials.

If this sounds interesting to you, go ahead and subscribe and I’ll see you again in the next video.

Thanks for joining me on our creative journey.

Now, go make something. Perfection’s not required. Fun is!

How to easily make a low-voltage, remote shop vac switch

Description

Controlling appliances remotely can be useful, but some ready made solutions are pretty expensive. Today Harley shows an inexpensive way he uses to turn his shop vac on and off remotely. The same items could be used to control any appliance remotely.

The central part of this system is the PowerSwitch Tail. It contains an electronically controlled switch to turn things on an off. There are a large number of ways to control this. In this episode, we talk about a very easy way to use this device. In future episodes, we’ll expand on different ways to control this switch that can be useful around the shop environment.

PowerSwitch Tail II (Amazon affiliate link)

For a written transcript, go to How to easily make a low-voltage, remote shop vac switch

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at http://incompetech.com
Sound effect: living-room-light-switch by alienxxx at http://freesound.org

Transcript

In the comments of “How to quiet a shop vac”, Rob liked the low-voltage remote switch aspect of how I control the vacuum and he asked “Can you show me an example and material break-down that could easily then be added onto?”

Today at the House of Hacks, I will talk about that very thing.

[Music]

Hi Makers, Builders and Do-it-yourselfers. Harley here.

When I converted my shop vac to a central, plumbed in system, I wanted a way to easily start and stop it. I went through a couple designs before settling on the one I used. Today I’ll show a variation on my design that's an easy way of controlling a shop vac with a simple wired remote.

While my application is a shop vac, you could actually control anything using this technique. In the future I plan to show some upgrades to this control, but for now, I wanted to keep it really simple.

Before I start, I do want to point out that there are ready made solutions from expensive to cheap. I’ve not tried any of these to be able to make any specific recommendations but I did want to mention them for the sake of completeness.

If you just want to get the job done without hassling with making something yourself, you might want to investigate these. But if you want something that’s got your own style to it, you want to learn something, you need something that’s not available off-the-shelf or just want to have the joy of making something, hopefully the following will help.

At the core of how I made mine is a device called a PowerSwitch Tail. This is a short cord that looks very much like an extension cord. It has a plug on one end and an outlet on the other. What sets this apart from other extension cords is it has an electrically controlled switch built into it.

On the side of this box are two connectors. When these connectors have between 3 and 12 volts DC applied to them, the main power is turned on. When there is no voltage on the connectors, the main power is turned off. It only draws up to 30 milliamps, so it’s pretty easy to control with electronics, like an Arduino or other digital circuitry.

However, the easiest way to control this is simply with one or more batteries, a bit of wire and a switch. In this example, I’m using some D cells because that’s what I had lying around, but a 9 volt battery would be simpler and smaller.

To use it, just connect the negative side of the battery to the minus connector. Connect the positive side of the battery to one side of a switch and the other side of the switch to the plus connector. Now, when the switch is on, the device will be on and when the switch is off, the device will be off.

And that’s the easiest way I know to remote control a vacuum, or any device. The cost of the PowerSwitch Tail is around $30 and the wire and switch is based on what you want to use. You may have something in your junk drawer that could be used, like a USB cable or network cable that could have the ends cut off. Switches could be scavenged from dead electronics.

Or you could get new materials. Low voltage wire is a couple cents a foot at the home improvement stores and they have a wide variety of switches for a couple dollars each. A box to mount the switch in could be anything from a disposable food container to something more robust. Just use your imagination.

As I mentioned at the start, I do plan to do follow-up videos talking about different, more capable, although more complicated, ways to switch the PowerSwitch Tail on and off.

In conclusion, let’s have a conversation in the comments about buying off-the-shelf solutions versus making your own, or anything else you’re interested in.

If this is your first time here at House of Hacks: Welcome, I’m glad you’re here. We’d love to have you subscribe. I believe everyone has a God-given creative spark and through this channel I hope to inspire, educate and encourage makers in their creative endeavors. Usually this involves various physical media like wood, metal, electronics, photography and other similar materials. If this sounds interesting to you, go ahead and subscribe and I’ll see you again in the next video.

Thanks for joining me on our creative journey. Now, go make something. It doesn’t have to be perfect, just have fun!

How to rebuild a lamp

Description

A quick overview showing how to replace the switch in a shop lamp.

Transcript

Hi Makers, Builders and Hackers. Harley here.

I've got this nifty little shop lamp that I picked up a number of years ago. I think I got it when I got either my band saw or my drill press. And it's really handy. I think I got it a Woodcraft for like $20 or something like that. And it's got a magnetic base so you can stick it on the metal table of the tool or on the side of the tool itself. And it's got multiple points of articulation so you can move the light where ever you want it. Extend it out or crimp it in. It's got a couple points where it pivots on the base and on the lamp itself so you can move the lamp where ever you really want it. It's just a really handy little lamp and inexpensive. Last time I went to use it however the switch just would not switch. It was completely frozen up for some reason. So I'm going to take it apart and see if I can see what's going on with it and see if I can fix it.

In taking everything apart, I can not see from visual inspection what's going on. It's just... It doesn't really come apart any further than this. There's a couple rivets in here and if I really wanted to get ambitious I could drill it out, but then I'd never be able to put it back together. I did notice in taking it apart that there's some plastic melted looking bits right here where it looks like it got really hot and melted the plastic a little bit. I'm guessing... As I was taking it apart I noticed I have a 100 watt bulb in here and I also noticed that the... inside here it says "use 60 watt type... or smaller bulbs." I think I may have just overheated it and melted the thing. So, the moral of the story here is... use... don't put a larger bulb in here than it was designed for.

I did go to Home Depot, or Lowe's I guess it was, and picked up another switch. I'm going to take it apart and see if it will work. It's the same type of switch. It looks on the surface like it's a good match. In fact, as I look at it now, it looks like an exact match. So, I'll take it apart and see if it fits in the fitting and hopefully it'll be working here in a minute.

Yay! It works. It was an absolutely perfect fit. This piece I got at Home Depot looks like it was exactly the same part and it fit without any problems whatsoever. And so, I'm glad. Got my little lamp back and I can start doing some band sawing now. Awesome.

Until next time, keep on hacking. It doesn't have to be perfect, just have fun.