A Peltier Dewar

CCD is an important component for the astronomical observation.Because of the noise and dark current,CCD must be cooled to low temperature.Dewar is usually used as a container to cool the CCD.It is a very important component for the terminal in the astronomical use. There are two kinds of dewar:the LN₂/LHe dewar and the thermoelectric cooling dewar. We have set up a Peltier (thermoelectric cooling) dewar recently.In this article the principle of thermoelectric cooling and the particular use of thermoelectric cooling are illustrated.The necessity of the thermoelectric cooling dewar is also analysised.In the design,there are two pieces of Peltiers to cool the CCD.We provide the regulate voltage to the second cooling pile,and the current of the first cooling pile is controlled to get stable low temperature for the CCD.The cooling temperature can be changed when needed.And mechanical structure of the thermoelectric cooling dewar is introduced in this paper. In the end of the article,the experiments for the circuit of temperature control are described and the preliminary results of the experiments are also given.It is shown that the disturbance is less than ±0.1℃.