Video thermometer and humidity indicator

This paper describes the features and design details for a video thermometer and humidity indicator (VTHI) The VTHI displays the ambient temperature and relative humidity on a NTSC standard television screen. The goal is to overlay the character information on top of a background video display. This will allow the user to get the desired information without interrupting the program. The temperature and humidity data will remain on the screen for five seconds. The displayed characters will be white with a black background. The circuitry required for this design includes temperature and humidity transducer interfaces, sync separation circuitry, digital timing and character generation circuitry, and video switching and amplification circuitry.