Peltier Based Novel Heat Pump for flow Cell in Automated Analyzer Using PWM Techniques

Temperature control is an important parameter in analyzing the blood samples in bio-chemistry analyzers. Besides temperature control at certain accuracy in analyzer, it is more important to achieve the set point temperature (SPT) in a very short interval of time, normally within 5-6 seconds. This fast thermal response is achieved by using peltier element. Peltier element works on the principal of Peltier Effect. In the presented work, a PID based heat pump is designed in order to achieve the required set point temperature at the possible fastest rate. The proposed system works using two power transistors in tandem with combination of N-P-N and P-N-P power transistors that source and sink the current through the peltier device attached with the system body.