Abstract: In an electronic video monitoring system for security and surveillance, a recording device can improve image quality, particularly in a night mode, while conserving battery power, by repeatedly activating an infrared (IR) light while capturing a video image, then deactivating the IR light and activating a visible light while capturing another video image, then blending the captured images to produce a blended video image. The blended video image can provide color in a foreground for improved detail where such detail is typically most important and grayscale in a background for effective monitoring of a broad field of view. The IR and visible lights can be controlled by Pulse-Width Modulation (PWM) signals having duty cycles which can differ in various modes to achieve differing effects.

Abstract: A real-time clock circuit for saving real time information during removal of a battery is presented. The battery provides power to the clock circuit during a steady-state mode. The clock circuit includes an oscillator assembly for generating a periodic waveform. A counter accumulates real time information in response to the periodic waveform. An energy storage device is coupled to the counter to supply energy to the counter while the battery is removed. A switch is coupled between the battery and the energy storage device to prevent the energy storage device from supplying energy to components other than the counter during removal of the battery. The switch provides a path for energy to flow from the battery to the energy storage device, thereby charging the energy storage device.