What are environmental control units?
Environmental control units (ECUs) are devices that allow people with mobility impairments to operate electronic devices, including televisions, computers, lights, appliances, and more. There are many commercially available ECU devices, however they typically fall into two broad categories—stand-alone and computer-based devices.
As explained in the article Everything You Need To Know About Environmental Control Units, "stand-alone ECUs contain their own electronics and do not utilize a computer to function. Many of these units can be activated by a switch, which acts as the interface between the user and the unit." In contrast, a computer-based ECU "consists of a software program and the necessary peripherals that allow a computer to function as an ECU".
According to the Delaware Assistive Technology Initiative there are currently four basic types of ECUs available. They are:
- AC power. This type of system uses the electrical wiring already in your home. Each item to be controlled (lamp, radio, etc.) is plugged into a control box, which in turn is plugged into an electrical outlet. The user has an input device that communicates with each control box via the existing wiring system. A different control box is needed for each appliance. These systems are inexpensive and easy to install.
- Infrared. These ECU devices send an infrared signal to the control unit, which in turn sends another infrared signal to the appliance. This type of ECU is seen in most of our TV and VCR remote controls. In order for the device to work, the remote must be aimed directly at the control box with nothing blocking its path.
- Radio control. With this type of device, the remote sends radio waves to the control unit, which then sends the message to the appliance. This is the same technology that powers garage door openers. The remote and the control box can be in different rooms and still work, but the system has a range limit of 50-200 feet. Interference from another nearby control unit is also possible.
- Ultrasound. This type of ECU uses high frequency sound waves as the input and output signal. The sound wave will bounce around the room until it reaches the control box and delivers its message. The control box then sends a command signal to the appliance being controlled. The input device and the control box must be in the same room to work.
No matter which type of ECU you select, be sure to have a backup system in place in case of power failure.
For more information on selecting and purchasing an ECU you may wish to read the articles DATI Assistive Technology Facts: Switches and Environmental Control Units and Ten Tips For Choosing an ECU.