Add Auto On/Off to Your AV Gear with This IoT Control Relay


After installing my bass shakers, which you can read more about in the article linked here, I was left facing an unforeseen obstacle. I could not get my bass shaker amp to turn on along with the rest of my system because it did not have a 12-volt trigger input. Therefore, it could not turn on automatically when I turned on my receiver. This was a bit of a hassle because I strive for my home theater setup to be as simple as possible.

I was not sure what to do initially, so I decided to ask for advice on the AVS forums. Luckily, some helpful folks there had a great suggestion – an IoT Control Relay device you can find on Amazon. They explained that this device could manage the power supply to outlets with the trigger output from my AVR.

I was curious about this solution, so I wasted no time ordering one and giving it a try.

What is a 12-Volt Trigger?

A 12-volt trigger is a low-voltage signal that is used to turn on or off other AV equipment such as amplifiers, subwoofers, or projectors. It is typically carried over a simple 2 conductor wire with either a 3.5mm stereo mini-jack (left) or bare wire that is terminated in a screw terminal (right) where you insert the two wire leads.

Example of 12V trigger 3.5mm jack on the back of a Denon AVR.

Example of 12V trigger screw terminal.

To use a 12-volt trigger, you would connect the trigger output from a source device to the trigger input of another device. When the first device is turned on, it will send a 12-volt signal to the second device, which will then turn on and stay on. Then, when the first device turns off, the 12-volt signal will disappear and the second unit will turn off. This allows you to easily turn on and off all of your AV equipment with a single button press.

12-volt triggers offer significant utility in home theater systems, where multiple devices often require precise sequencing or automatic activation. These triggers find common application in various scenarios such as enabling the control of external amplifiers in an Audio-Video Receiver (AVR) setup, managing motorized screens, operating projector lifts, and overseeing lighting systems.

Now this is awesome if your devices have a 12-volt trigger input, but what if your device does not? This is where the IoT Control Relay comes in.

IoT Control Relay

The IOT Control Relay is a pretty simple device designed to enable the management of AC power using a low-voltage control source, such as the commonly used 12-volt triggers found in AV equipment. Essentially, it functions as a 4-outlet power strip equipped with additional circuitry and relays, allowing each outlet’s power state to be controlled individually using the trigger signal. The device provides a total maximum load capacity of 12 amps, which is sufficient for most applications, though it may not be suitable for powering the most powerful amplifiers.

Among the four outlets, two are labeled as “normally OFF.” These outlets initially remain in the “OFF” state when the device is plugged in and powered on. They only activate when a 12-volt signal is active, making them ideal for applications where you want to add a 12-volt trigger to a device to turn on/off the outlet when other devices are turned on/off.

There is one outlet labeled as “normally ON,” which operates in the opposite manner. By default, this outlet is in the “ON” state when the device is first powered on and switches to the “OFF” state when a 12-volt trigger signal is sent. This is ideal for applications where you would want the device to turn off when other equipment turns on.

The outlet labeled as “always ON” acts as a pass-through outlet that is not affected by the 12-volt trigger. This feature is particularly useful as it ensures that you do not lose the functionality of a normally operating outlet when you connect this device to your setup.


  • Operating ranges: AC input 90-120VAC; Current 0-10A with longer 18AWG power cords, 0-12A with 16AWG cords
  • 12A thermal circuit breaker
  • Rated for 5.3 million cycles
  • Control voltage 3-48VDC or 12-120VAC
  • Debounce protection
  • Input connector: C-13/C14; Output: 4x NEMA 5-15
  • Indoor use only -35F to 145F
  • 1-Year Warranty


The initial step was to connect a 3.5mm trigger wire to the device. Since the device exclusively featured screw terminals for input, a 3.5mm cable with one stripped end was needed. This could be accomplished by either modifying an existing 3.5mm trigger cable through cutting and stripping it, or by acquiring a pre-stripped trigger cable. Given that I did not have any spare 3.5mm trigger cables on hand, I opted to purchase the necessary cables which can be found here.

Following that, I connected the stripped end of the cable to the removable terminal connector, ensuring that the red wire was connected to the positive (+) terminal and the white wire was attached to the negative (-) terminal. Then, I inserted the connector back into the relay box.

That concludes the setup process for preparing the device for use. The next step involved integrating it into my AV rack and connecting my devices. I proceeded by attaching the other end of the 3.5mm trigger cable to the trigger output on my Emotiva BasX A3 External amplifier, which was already linked to the trigger input from my AVR. Subsequently, I plugged my bass shaker amplifier into one of the “normally OFFF” outlets on the IoT Relay and powered up the device.

That was it, it was ready to go.

Closing Thoughts

I have had this device running for about a month now and have completely forgotten that it exists, which is a wonderful thing. It just works, no fuss and no mess. It is a simple and easy solution to a problem that would otherwise be a bit complex to solve if the device does not have a 12-volt trigger input.

A potential improvement for this device could involve giving users the ability to customize the outlet functionality to better suit their needs. This, however, falls more in the realm of a wishlist item, as the device’s current performance already meets my needs perfectly.

Overall, we recommend the IoT Control Relay to anyone looking to add automated on/off control to their AV setups, as it is incredibly simple to setup and use.

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