-------------------- Tech Support Tips/Troubleshooting/Common Issues --------------------

Designed for Wall Outlets

If this is not working, make sure the PowerSwitch Taill II has the plug plugged into a 120 volt AC outlet. Another support representative indicates that the relay inside won’t work without AC power.

Jumper

Even though the data sheet we list doesn’t say so, a customer reports that there is a jumper inside these that let you select NO or NC relay contacts. The datasheet will have more information about the jumper inside the enclosure.

A question...Is it UL listed? I don't see any markings to signify that it is.

Is this either "normally open" or "normally closed"? If NO, then how hard it is to rewire to NC - or can that be easily achieved with the microcontroller?

Need 240 VAC version for Europe.

Looking at the instructions / schematic, the "ground" pin is just hooked to the 3rd prong AC ground.. I should be able to ignore that pin then, right? All the low voltage DC side electronics are completely isolated from this anyway, and so this looks pointless to me..?? Am I missing something?

Shouldn't I just be able to hook up ground and a digital pin from an arduino and work this thing just fine?

A 240v version with IEC plugs would be ideal for us non-us folk.

Finally, a Sparkfun product that doesn't try to kill you.
It sure beats the old relay on the bench with test clips trick. It only works with 120 VAC, but it's controllable with a single I/O port at 3V to 5V. I'd leave the ground terminal unconnected to avoid a possible ground loop; it's fully isolated anyway.
Plus it costs less here than from the OEM. Gotta have it!

This is a very cool product. But if you are just looking for an easy way to avoid being exposed to high voltage, an alternative is to modify one of those remote controlled switches. They are wireless and come with a remote and one or several power sockets. You can get them in many retail or online stores for cheap. All you need to do is to modify the remote -- use a MCU to simulate a button press, (often as simple as sinking one button pin to ground). I've tried this before and it works quite well. And it's even wireless!

(Update) check this page: <a href="http://rayshobby.net/blog/?p=936">http://rayshobby.net/blog/?p=936</a> for example.

So... Why not just buy a relay?
Two of these: http://www.sparkfun.com/products/10636 in parallel would be rated at one amp higher, and all for less than half the price of this.

If anyone wants some Arduino example code, see the following. This makes it so when you press a button it goes on for as long as you press it.

Button is connected to Ground and 2. Relay is connected to 13, 5 volts, and Gnd.

Code:

const int relayPin = 13;  //change these to change pin numbers
const int buttonPin = 2;

void setup() {
pinMode(relayPin, OUTPUT);  //initializes the pins defined above
pinMode(buttonPin, INPUT);
} 
void loop() {
if (buttonPin == LOW) {    //if the button is grounded
digitalWrite(relayPin, HIGH);     //turn the relay on
else {
digitalWrite(relayPin, LOW);  //if the button is not grounded, turn the relay off
}
}

Edited to clarify.

These sell out to quick but I found a good video on how to make one of these. DIYPowerTail

Bought this problem and have a problem getting it to work. I supply a drive from a signal generator (2 s pulse), the LED lights up but the connected device doesn't get powered. When measuring the output voltage, without a drive signal, the voltage reads 122V, with no load attached this goes down to 115V (line Voltage) when drive signal is applied. No sound audible from the relay switching.

Any idea what might be wrong besides that the device is faulty?

I keep putting moving this back and forth between my wishlist and shopping cart because they always seem to be out of stock when the rest of my order is ready. Just wondering, is it because they are really popular, or is supply really scarce, or what? Seems like they would not be that hard to make and it surprises me that someone hasn't come up with a competitive product with a bit more constant supply.

I try to control the on off of a LED light bulb, in the on position the bulb light up very bright but in the off position the bulb still has a extremely dim light (not totally off), is it normal?

When will this be back in stock?

A while back, I found a device that looked like a octopus, with each of its arms being an outlet that was controllable by a build in relay. Does anyone know what product i'm talking about? Any help would be greatly appreciated. Thanks

Do you sell just the PCB? I wanted to make an Arduino clone on a perfboard and solder wires to this.

Edit: Never mind. Found a Sparkfun schematic for a relay control thingy and I soldered it up on a stripboard and it works! Find the schematic that I used here, just scroll down to the schematic.

Did this go up in price or am I misremembering?

A demo code example for mbed with photos and a video is available at http://mbed.org/users/4180_1/notebook/powerswitch-tail-ii/

Woohoo back in stock. Let's see how long these last.

Dang!! Out of stock already? Any idea when you guys will get more?

Where there be one with european plugs (2 round pins) ?

How fast can this be cycled? Enough to do fading/pwm?

Wow, I've been building these things for years now at work to switch equipment on and off in unison with other equipment.
I had a crappy cable modem a while back that would randomly lock up, so I set up a cron job on my firewall box to ping a server periodically.
If it didn't get a response, it would pulse one of the parallel port's polling lines that was connected to a relay in line with the cable modem's power.
It's nice to know I can get them ready-made now. That will make my boss happy.

What's the max inductive load? I'm thinking about controlling a small air conditioner (or maybe refrigerator) with one of these.