1. The problem statement, all variables and given/known data I need to design a circuit that measures the temperature of a tank of water (using presumably a thermistor) and then displays the temperature by lighting just one of three led lights. For example, if it is too hot, the only the first LED lights up, if it is too cold only the second will light up, and if it is in the correct temperature range, then only the third will light up. I think I'm ok to use Op Amps, if that helps, but I cant use microcontrollers etc. Thanking you in anticipation. Greg136 2. Relevant equations 3. The attempt at a solution I could get this to work should I only need 1 LED, or possibly even 2, but I have no idea how I can get 3 LEDs working independently from one another.