Abstract: An air pumping device used in an aquarium with a silencing effect, the device mainly has a housing, the housing is used to receive therein an air pump and a coil unit able to generate an alternating magnetic field; and the housing is formed therein a sealed silencing chamber covered with a covering plate. The silencing chamber has therein partitions to divide it into a front silencing chamber and a rear silencing chamber. When the air pump is operated, air is led firstly into the front silencing chamber, the air flows through the air pump and then is led into the rear silencing chamber; after an action of buffering, the air exhausts from the housing through an end of the silencing chamber.

Abstract: An adjustable illuminating lamp for an aquarium that mainly has an illuminating main body for receiving a lamp pipe, the illuminating main body is provided on its two lateral ends each with an extendible rod, the extendible rods can be adjusted in their distances from the illuminating main body, and the end of each extendible rod is provided with a clamping means to clamp on either of the lateral sides of the aquarium.

Abstract: A temperature detecting heater with an indicating structure for an aquarium, the temperature detecting heater mainly has an indicating structure including a control circuit and a two-color LED indicating lamp in its circuitry. After the temperature detecting heater is turned on, temperature detectors of the control circuit detects a voltage to compare it with a reference voltage at a set point; when the temperature at the detected point is lower than that of the set point, a heating element of the temperature detecting heater is controlled to work normally and makes the LED indicating lamp show a first color, for instance, red; but when the temperature at the detected point is higher than that of the set point, the heating element of the temperature detecting heater is controlled to stop working and makes the LED indicating lamp show a second color, for instance, green.

Abstract: An improved structure of a temperature sensor of an electric heater being provided with an outer pipe of which one end is tightly sealed, and being provided therein with a plurality of electric heating elements positioned on a supporting plate and connected with a control circuit board for electric conducting from an external power supply, the control circuit board is provided with a high-temperature sensing element, the high-temperature sensing element is serially connected on the control circuit board with a water-temperature sensing element. Thereby a safer function of use can be provided when the structure works under water wherein the electric heating elements can be automatically shut.

Abstract: A method for controlling an output power of a fuel cell is disclosed. A DC converter and a fuel cell are provided, and a voltage input end of the DC converter is connected to a voltage output end of the fuel cell. The DC converter is used to convert an input voltage of the fuel cell into a regular output voltage. The DC converter is also used to retain a voltage of the voltage input end of the DC converter within a predetermined range, and thereby an output voltage of the fuel cell is maintained within the predetermined range. The predetermined range of the voltage is set according to a number of membrane electrode assemblies in the fuel cell and a voltage of the membrane electrode assemblies generated in an extent of optimal power.

Abstract: An electrical circuit interface board for connecting a fuel cell is described, which includes a substrate, an electrical circuit, a first interface, and a second interface. The electrical circuit is disposed on the substrate. The first interface is disposed on the substrate for electrically connecting the fuel cell, and is electrically connected to the electrical circuit. The second interface is disposed on the substrate for electrically connecting an electrical device, and is electrically connected to the electrical circuit. It becomes feasible to manage the fuel cell through the electrical circuit interface board.

Abstract: A pond heater with a water pump, the housing of the heater is provided with a holed seat for receiving the water pump; cold water enters the pond heater via a water inlet, and hot water generated by the heater is discharged from a water outlet to create convection in the pond to increase effect of ice removing.

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: A device for controlling a wire cut electric discharging machine is provided with a testing circuit to detect the condition between the wire electrode and the workpiece before every discharge process so as to regulate the discharge energy according to one of the detected conditions: normal discharge, arc discharge, or short circuit. The device includes two switching transistors controlled by a control unit according to the comparison result between a reference voltage and the voltage measured between the wire electrode and the workpiece being processed.