Inner Workings - QSC DCA1222 User Manual

Basic Functional Block Diagram of PowerLight™ Supply

INNER WORKINGS

An impressive amount of technology is packed "under the hood" of a DCA
Series amplifi er. Thousands of watts of power fl ow inches away from state-of-
the-art low noise inputs. Precise circuit layout and thorough protection assure
that all of this activity occurs smoothly and safely. So, what actually happens
when you turn on the power switch?
Soft Start Sequence. The fi rst task is to charge the primary energy reservoir
without drawing a large surge current. A special inrush limiter allows just
enough current to charge the energy bank in three seconds. Meanwhile, a
low-power switching supply provides power to start up the main supply. After
three seconds, a relay bypasses the inrush limiting and full power operation
is enabled. The audio circuitry mutes for one second to eliminate start-up
thumps. When the red CLIP lights go out, the amplifi er is ready for action.
PowerLight Technology. High current switching devices draw over 10,000
watts of peak power from the main energy reservoir, which is replenished
directly from the AC line for maximum stiffness. Conventional amplifi ers must
isolate the energy bank with a large AC transformer, which weakens the fl ow
of current, allows greater sag under load, and produces hum. The PowerLight
supply performs voltage conversion at a very high frequency, allowing better
coupling through a much smaller isolation transformer.
内部工作元件
DCA 系列放大器的"罩壳下"包含相当多的技术。数千瓦的功率
将逐渐通过最先进的低噪音降低输入端。精确的电路布局和彻底
的保护可保证所有活动顺利和安全地进行。因此，当您打开电源
开关时，实际上会发生什么呢？
软启动顺序。第一个任务是为主要电能池充电，而不吸收大量涌
流。特别的涌入限制器使刚好足够的电流对电能池充电三秒钟。
同时，低功率开关电源为主电源提供启动电源。三秒钟后，继电
器绕过涌入限制并启用全功率操作。音频电路静音一秒钟，以消
除启动噪音。红色削波指示灯熄灭时，放大器就准备好开始工作
了。
PowerLight 技术。高电流切换设备从主电能池吸收超过 10,000 瓦的
峰值功率，主电能池则直接从 AC 线路补充电能，以保持最大电
容。传统放大器必须使用大型 AC 转换器隔离电能池，这会削弱
电流，使电流在负载下进一步降低，并产生噪声。PowerLight 电源
用超高频率执行变压，通过更小的隔离变压器实现更好的耦合。
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