Monitor alarm and indicator display multiple deviation boundaries

摘要

A low-cost monitor can visually indicate a process problem, such as a failed cabinet fan or otherrnhigh- or low-temperature characteristic. The microcontroller-based circuit in Figure 1 provided a simple visualrnindication of both the direction and the magnitude of the temperature's deviation from a user-set mean in a solder pot. Using a Microchip 12F675 controller, the coded sequences allow the user to both set the mean and scale the range of the monitored variation.