| 摘要 |
PURPOSE:To attain ease of assembling and to reduce generation of noise by controlling a current flowing to a peltier element with two triacs and adopting the zero cross switching system to the on/off control of the triacs. CONSTITUTION:Triac pairs 11, 13 are connected in parallel between the peltier element 5, and the on/off state of the circuit is switched by a gate control circuit 15 connected to a gate of the triacs 11, 13 depending on the polarity of an output AC voltage of a transformer 25 and the direction of current flowing to the peltier element 5. The current and its direction flowing to the peltier element 5 are controlled suitably by the constitution above. Further, since the zero cross point of an AC signal is taken as a timing of control and switching, the generation of noise is decreased. |
