降压升压转换器有助于延长电池寿命的运动检测

　　降压升压转换器有助于延长电池寿命的运动检测

　　许多安全和运动检测系统依赖于易于安装的小型、半自治节点。这意味着使用电池为基础的电源和低功耗操作，以尽量减少电池的数量在产品的使用寿命的变化。

　　在其寿命期间，电池的输出电压下降，当电荷接近完全耗尽时最大下降。一个转换器的类型，可以适应这种变化，在电压但仍能提供较高的电压传感器和射频发射器的Buck-Boost变换器–操作电路的降压部分当电池是新鲜的，以增加运行时的电压低于阈值的电子电路，它的权力。许多供应商已经开发了集成的降压-升压转换器，用于电池系统的优化，本文讨论了其中的一些，包括AMS、模拟设备、线性技术、半导体和德克萨斯仪器的设备。

　　运动检测已经成为现代安全系统的一个组成部分，在家庭或办公室应该是空的时候，监视入侵者的迹象。随着时间的推移，我们将看到新的应用程序，将运动检测扩展到日常生活中，使我们能够控制照明和媒体设备，通过使用手势。在家中传播的设备将监视这些关键的手势，使用先进的信号和图像处理技术来区分对系统重要的自然动作和手势。

　　An important link between these systems is the need for distributed， low-energy sensors that can run from batteries to avoid the need to rewire the home to install new systems. They communicate with each other and central processing nodes using low-power radio protocols and use various forms of sensing technology， such as ultrasonic or low-resolution video， to analyze the motion of people.

　　Some types of sensor require high voltages to operate that cannot be generated from the battery cells themselves， or there may be a requirement for a backlight LED or a built-in status display， which needs a high-voltage power source to operate. One option for a step-up or boost regulator is the ON Semiconductor NCP1403. The device is designed to boost a single lithium-ion cell or two AA or AAA cells up to voltages as high as 15 V.

　　In systems that use low-voltage sensors， it is still desirable to have the step-up function available. Simple low-power operation is not enough to eke out the life of a battery. The discharge profile of a typical cell means that it will only deliver its peak voltage at or near the full charge. As the battery discharges， its output voltage will fall， potentially below the supply voltage for which the system has been designed. There is often a very large drop close to full depletion. However， the battery still has energy it can deliver if the surrounding circuitry can make use of it. In reality， the battery rarely empties before it needs changing – it simply cannot deliver usable energy. For example， a 1.5 V AA alkaline cell will generally be considered ‘empty’ when its output voltage falls below 0.9 V.