February 23, 2010
| by Garth Powell
Projectors and Certain Displays
- All lamp-based video projectors (including older rear-projection DLP and LCD televisions) contain bulbs that must cool after use or they risk permanent damage. Video projectors automatically cool bulbs with a built-in fan, which typically runs for eight to 10 minutes after the projector has been switched off.
However, if the power is suddenly lost due to a power blackout, and the projector has been operational for a number of minutes or hours, a costly bulb may end up requiring replacement.
Protecting projectors with a UPS system can provide significant savings in replacement lamps. Also, more and more displays are integrating networking or data storage, necessitating backup to keep data safe.
Satellite Receivers and Cable Boxes - Many satellite receivers and cable boxes store the television program schedules in volatile memory. After recovering from a power loss it can take a very long time to retrieve all of the information. Additionally, many satellite receivers and cable boxes also have DVR functionality which employs a hard drive.
Don’t Do This
Don’t connect displays and high-current audio devices to a UPS: Devices that do not risk data loss or do not need to continue running in a blackout will not benefit from connection to a UPS, and in fact, battery backup may hinder the performance of both the connected equipment and the backup unit itself due to specific circuitry within a UPS device such as regulated power supplies.
Displays - Aside from the projectors and displays mentioned earlier, most display devices do not require a UPS as they will return to full operation as soon as power is restored.
Newer energy-efficient LED and LCD screens notwithstanding, many displays have high energy requirements that will quickly drain a battery, reducing backup runtime for more critical components. Furthermore, while some UPS systems incorporate AC noise filtering, they may not feature the far more sophisticated linearized filtration that displays need for optimal video quality.
For the best performance from your display, provide a power management solution with adequate surge protection and a linear noise filtration circuit.
Audio Equipment - Most audio equipment such as audio receivers, power amplifiers, and powered subwoofers will not benefit from connection to a UPS. When volume levels are pushed during a dynamic passage or theatrical explosion, power amplifiers need a quick supply of current to achieve the optimal sound.
However, a high-impedance UPS acts like a clamp, restricting the transient current the power amplifier so desperately needs. Further, as with a display, many audio components will drain the battery very quickly, and filtration may not be sufficient for optimal performance.
Seek Specialized A/V Products
When specifying your power management system, be sure to not only remember battery backup, but use the right battery backup products.
Many power management manufacturers now provide UPS solutions specifically for A/V systems, meaning their filtration and protection have been optimized for audio and video equipment as opposed to computer equipment.
Ideally, a home theater power management system will either a hybrid UPS/Power Conditioner for smaller systems. These products provide a bank of outlets with battery backup and other outlets for high-current or non-digital components.
For larger systems, a combination of UPS for digital equipment complemented by a variety of power conditioners or regulators for all ancillary equipment, is ideal.
Garth Powell is senior product designer for Furman
, developers of A/V signal processors and AC power conditioning and distribution products.