Precision universal temperature ( −200°C to +200°C) controller with fast solid state on-off system
Amitava Chatterjee, S. C. MUKHERJEE · International Journal of Electronics · 1993
A simple, rugged, reliable, low cost temperature display-cum-controller has been designed and constructed using standard integrated circuits and a 3½ digit LED display. The controller, utilising semiconductor controlled rectifiers as fast solid state on–off switches capable of maintaining the set temperature constant within the temperature range -200°C to + 200°C with a resolution of ±0·05°C. A thermocouple (specifically, a copper-constantan type) sensor has been used because of its fast response time and tolerance of high magnetic fields.