Abstract: In the structure of an air pump with low noise, the diameters of an inlet and an outlet in the main body of the pump are reduced (such as 1.3 mm) to be smaller than that normally used (such as 2.0 mm), and the areas of air control films used are coincidently reduced, the cross-sectional area of a noise-silencing channel is also set in coincidence with the areas of the inlet and the outlet. Thereby, sounds generated by repeated beating of the air control films on the inlet and the outlet against the inner walls of the main body of the air pump can be reduced; thus noise in operation of such an air pump can be reduced too.

Abstract: An aquarium water temperature controller, which includes a glass casing, an inner tube mounted within the glass casing, an electric heating element mounted in the glass casing and connected to the inner tube, and a circuit board mounted in the inner tube and electrically connected to the electric heating element, wherein the circuit board includes a bridge circuit having a thermistor, a comparator circuit controlled by the bridge circuit to output high/low potential subject to temperature detecting status of the thermistor, a bias voltage generating circuit connected to the bridge circuit and the comparator circuit, an analog switching circuit controlled by the bias voltage generating circuit, a thyristor, and a voltage following circuit and an integrating circuit controlled by the analog switching circuit to turn on the thyristor when the bridge circuit outputs low potential, or to turn off the thyristor when the bridge circuit outputs high potential.

Abstract: An adjustable multi-pattern miniature fountain sprinkler including a base, adjusting mechanisms, and a cover. The base is connected to a water duct disposed at a bottom side thereof. A plurality of water holes are formed in the bottom side of the base. The adjusting mechanisms consists of an upper adjusting seat and a lower adjusting seat coupled together and fitted within the base. The adjusting seats respectively have a bottom surface provided with a central hole which extends outwardly to form sector-like holes. The cover consists of a cover plate and a stem extending from a bottom side of the cover plate. The stem is fitted through the central holes of the respective adjusting seats. The cover plate has a peripheral rim provided with a multiplicity of inclined indentations adapted for providing a spray of water of multiple water levels and water patterns.