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 replace intermittent connectors

Description

Sometimes plugs fail. Today at the House of Hacks we tear down a Better Life Devices BLD T250 transdermal stimulator to change the plugs from unreliable barrel connectors to more reliable 1/8" audio connectors. The general process can be used for any type of small device.

Referenced video: How to desolder electronics

For a written transcript, go to How to replace intermittent connectors.

Music under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at http://incompetech.com
Incidental: "Dispersion Relation" by Kevin MacLeod at http://incompetech.com

Transcript

This medical device is going to get an upgrade today at the House of Hacks.

My wife has chronic back issues and the other week had a big flair up. The chiropractor showed us a home electronic stimulation unit that he was willing to sell us at a very steep discount because he wasn't terribly impressed with their reliability. He said they worked fine as long as they worked but reported they had a tendency to develop intermittent faults and then fail altogether.

As I looked it over, before buying it, I noted the connectors on the side. A similar design used to be standard for photography flashes and is a well known failure point. I guessed that this was probably the problem but, if it wasn't, figured it would be easy enough to figure out what was.

So we went ahead and bought it, knowing I would probably have to fix it at some point.

Sure enough, after about two weeks of use it started working intermittently. In this episode, I'll show how I upgraded this with a more reliable solution.

At the local electronics store I got a couple 1/8" audio extension cords. The plan was to cut the ends off and put one end in the device coming out as a pigtail and splice the other end onto the wires for the pads.

But first I need to open the unit. I start by sliding this cover off, taking off the two knobs with a gentle pull, they're just press fit on, and removing the battery. It's a good idea to make sure the power is disconnected before doing any sort of repair on electric devices.

Next is to open it up. This took me a little bit to figure out as there are a couple hidden screws. The first one is under this label. Fortunately the label is made out of thick plastic and held down with some sticky but removable adhesive, so it peels off without too much trouble. Once off, a philips head screw is revealed.

There's another screw on the back under this belt clip. One side of this clip has a slot designed to slide a screw driver into. Lift up with a fair mount of pressure to pop off the clip. And there's the second screw.

Finally there are two plastic clips accessed through the battery cover. Pulling the two parts of the case apart at the bottom causes those clips to pop apart and the case finally separates.

The circuit board simply rests in place. To remove it, the LEDs may have to be slid out of the holes in the case before lifting the board out.

And that completes the disassembly.

These are the original cables with their problematic ends. They plug into these connectors on the board.

These will be replaced with the ends from this audio cable. I'll cut the ends off the cable and replace the connectors on the board with the female audio connector and splice on the male audio connector onto the end of the electrode cable. This will result in a much more reliable connection.

To remove the connectors, I'm just going to use a bit of desolder braid to remove the solder. Once the solder's removed, the connectors just drop out of the holes.

This is a cheap brand of audio cable that I've had about 50% failure rate with. So before doing anything to this cable, I'm testing it with a simple continuity check. I make sure I don't have any shorts between the tip and ring and that I do have continuity between the tip on both ends and the ring on both ends.

Now that the cable checks out, I'm just going to cut off the ends. Then using some wire strippers I'll carefully remove the insulation. With audio cables, the outside conductor is wrapped around the inside one. So after taking off the outside insulation, the wires first need to be gathered together and twisted. Then the insulation can be taken off the inside conductor.

And then the other end gets the same treatment.

With the connectors exposed and twisted together, now I'll tin the ends. This makes it much easier to solder when things are put together.

Now the wires just go in the holes the old connectors came out of. For this particular application, it doesn't matter which wire goes in which hole. For other types of devices, the outside ring should match up to the outside ring on the original.

A little solder finishes the connection and then the excess wire can be trimmed off.

That finishes the electrical side. Now a dab of hot glue makes a mechanical connection to act as a strain relief so there's no undue stress on the solder joint.

Now to modify the cables that plug into the device.

Cut off the original ends and split the two wires down the center. Expose the wire with some wire strippers, twist the wire together, add a bit of heat shrink tubing on the wires, add some tinning to the wires and solder the new ends onto the old wires.

Generally, I like to make a mechanical connection before soldering, but this particular wire was too brittle to bend well so I used the solder as both a mechanical and electrical connection.

Finally slide the heat shrink over the connectors and heat it up to shrink it around the connection. In total there were three pieces of heat shrink tubing for each cable: one for each of the wires and a larger one around the whole thing.

And now it's time to reassemble the device. This is just the opposite of taking it apart. Drop the circuit board into one side of the box, sliding the battery connectors into place. The other side goes back on top with the new connectors coming out of the original holes. The screws go back in. The label is replaced and then the knobs slide back onto the controls. Finally, the battery can be placed in. Before the clip goes back on, I'm going to test it. Yeah, nothing like testing it on yourself. As I turn up the intensity I can feel it working. Success!

A side effect of using these connectors is they act as a strain-relief, break-away connection. If the control unit somehow has forced applied to it, like it drops out of a pocket, it simply comes apart at the new connectors rather than putting a lot of force on the wire/connector/PCB system like the original connectors did.

Finally, I'm thinking about making a DIY version of this device. If you'd be interested in seeing a video about this, let me know in the comments.

Thanks for watching and until next time, go make something, it doesn't have to be perfect, just have fun!