TECHNOLOGY BASICS: What are Advanced Power Strips

Technology Overview
Detect and deny power to unused electronic devices

An advanced power strip (APS) is equipped with one or more activity detection technologies to automatically shut off the power to the electronic devices plugged into the designated outlets on it. The activity detection technologies include:

  • Motion sensing: Use of a passive infrared (PIR) sensor to detect the presence of a user.
  • Current sensing: A built-in circuitry to determine active usage based on whether the current draw by the device, typically the computer or monitor, that is plugged into a designated outlet on the APS exceeds a certain threshold.
  • Computer activity detection: Use of a dedicated software installed on the computer to detect active usage of keyboard, mouse, or trackpad.

To avoid frequent switching, the activity detection technologies are typically paired with a adjustable countdown timer. The countdown timer constantly reset itself when activity is detected, and the power to the electronic devices is shut off only after no activity is detected during the entire countdown period.

A Tier 1 APS has two types of outlets, always-on and controlled outlets. The always-on outlets have constant power supply while the power to the controlled outlets will be shut off when the APS detects no activity. Computers and other devices, such as wireless router, that require constant power supply are plugged into the always-on outlets. Other electronic devices that can be turned off in the absence of an active user are plugged into the controlled outlets.

A Tier 2 APS, in addition to the always-on and controlled outlets, has a third type of outlet, typically called control outlet. Depending on the APS manufacture and design, either the computer or monitor is plugged into the control outlet. Tier 2 APS has some types of direct connections to the computer and can put the computer to either sleep or hibernate mode when no user activity is detected within the period of countdown timer. This feature makes Tier 2 APS even more efficient in saving energy compared to Tier 1 APS.

Similar to regular power strips, advanced power strips also offer safety features including surge protection, ground fault detection, and resettable circuit breaker.

When selecting APS, it is critical to differentiate between products designed for residential entertainment applications and products designed for workspace applications. APS designed for residential entertainment applications often use the infrared (IR) signal detection technology, the IR signal generated from handheld remote control devices for TV, set-top box, or other home theater/entertainment systems, to determine activity. In workspace applications, users are not engaging with the electronic equipment through any IR signal-generating devices, and APS designed for residential entertainment applications will not only fail to generate the expected energy savings but also result in unsatisfactory performance.