The invention provides an improved structure of a fish tank heater.The heater is a quartz tube with a top opening and a hollow tube body provided with a waterproof top sleeve, which is arranged with a power line with a positive wire and a negative wire.One end of the power cord extends outside the top surface of the quartz tube.The other end is placed in the quartz tube and connected with a circuit board with positive and negative printed circuits.Solder the positive wire of the power cord to the upper end of the positive printed circuit.And the negative wire is welded on the upper end of the negative printed circuit.It is characterized by:A temperature switch with two wires is connected at the lower end of the positive printed circuit.Solder one of the wires to the lower end of the positive printed circuit.The other wire extends downward and is fixedly connected with one end of the heating coil.A temperature fuse with one or two terminals connected with pins is arranged at the lower end of the negative printed circuit.One of the pins is welded to the lower end of the negative printed circuit.The other pin extends downward and is fixedly connected with the other end of the heating coil；With this setting,The temperature switch and the temperature fuse are set on the circuit board above the heating coil.It is not only convenient for the assembly of parts,And make the temperature switch and temperature fuse more accurate to the induction of the heater air burn.It can not only reduce manufacturing costs,And improve the safety of its use,For its main purpose.本創作係提供一種魚缸加溫器結構改良，該加溫器是於一頂部開口並套設有防水頂套之中空管體的石英管內容置一具有正極線與負極線之電源線，電源線一端延伸於石英管頂面外，另一端置於石英管內並接設一具有正極印刷電路及負極印刷電路之電路板，使電源線之正極線焊接於正極印刷電路上端上，而負極線焊接於負極印刷電路上端上，其特點是，於正極印刷電路下端接設一具有二導線的溫度開關，使其中一導線焊接於正極印刷電路下端上，而另一導線向下延伸並與加熱線圈一端固接，再於於負極印刷電路下端接設一兩端皆設有接腳的溫度保險絲，使其中一接腳焊接於負極印刷電路下端上，而另一接腳向下延伸並與加熱線圈另一端固接；藉此設置，達到讓溫度開關與溫度保險絲皆設於加熱線圈上方的電路板上，不僅方便零件組接的工作，且讓溫度開關與溫度保險絲對於加溫器空燒的感應更為精確，不僅能降低製造成本，且提升其使用的安全性，為其主要目的。
