Abstract: A ventilation fan includes a fan unit, a cover, a speaker and an outer cap. The fan unit has an air inlet and an air outlet. The cover is disposed on the air inlet and has an opening disposed corresponding to the air inlet. The speaker is detachably disposed on the cover. The outer cap is disposed on the air inlet. The cover is located between the fan unit and the outer cap, and the outer cap has a plurality of through holes configured as both of ventilation channels and sound output channels.

Abstract: A ventilation fan includes a fan and a housing. The fan includes a base, a scroll casing, and an impeller. The base is used for supporting a driving device. The scroll casing has an air inlet, an air outlet, a top portion, a bottom portion corresponding to the top portion, and a slope surface connecting the top portion and an edge of the air outlet. The top portion and the bottom portion together define a channel height, and the ratio of the channel height to the height of the air outlet ranges from 1.1 to 2. The channel height ranges from 110 mm to 200 mm. The impeller is disposed in the scroll casing, and the driving device drives the impeller to rotate. The housing is used for accommodating the fan, and has an opening corresponding to the air outlet of the scroll casing.

Abstract: A ventilation system comprises a ventilation fan with a lamp for installing to a ceiling having an installation opening. The ventilation fan comprises a housing, a fan module, a power box, a junction box and a lamp module. The housing has a first opening and an air outlet. The fan module disposed in the housing and comprises an inlet opening and an outlet opening. The outlet opening communicates with the air outlet. Three accommodation spaces are formed between the housing and the fan module at different corners of the housing and disposed away from the air outlet. The power box and the junction box disposed at two of the accommodation spaces. The power box has a first circuit board. The lamp module and the housing are located at opposite sides of the installation opening. The junction box is electrically connected to the first circuit board and the lamp module.

Abstract: A ventilation fan includes a fan and a housing. The fan includes a base, a scroll casing, and an impeller. The base is used for supporting a driving device. The scroll casing has an air inlet, an air outlet, a top portion, a bottom portion corresponding to the top portion, and a slope surface connecting the top portion and an edge of the air outlet. The top portion and the bottom portion together define a channel height, and the ratio of the channel height to the height of the air outlet ranges from 1.1 to 2. The channel height ranges from 110 mm to 200 mm. The impeller is disposed in the scroll casing, and the driving device drives the impeller to rotate. The housing is used for accommodating the fan, and has an opening corresponding to the air outlet of the scroll casing.

Abstract: A ventilation fan includes a fan unit, a cover, a speaker and an outer cap. The fan unit has an air inlet and an air outlet. The cover is disposed on the air inlet and has an opening disposed corresponding to the air inlet. The speaker is detachably disposed on the cover. The outer cap is disposed on the air inlet. The cover is located between the fan unit and the outer cap, and the outer cap has a plurality of through holes configured as both of ventilation channels and sound output channels.

Abstract: A dual input DC—DC power converter integrating high/low voltages can simultaneously or individually transfer the power from two input power sources respectively having voltages higher than and lower than an output voltage to a load end. If one power source is failed, the other power source can still transfer power normally. Moreover, if an appropriate control circuit is matched, the currents and powers of the two input DC power sources can be accurately controlled to accomplish tracking operations of the maximum power of each power source. The power conversion system can be exactly simplified to accomplish the effects of enhanced efficiency and lowered cost and also have the advantage of simultaneous transmission of power from two voltage sources to the load end.

Abstract: A dual input DC-DC power converter integrating high/low voltages can simultaneously or individually transfer the power from two input power sources respectively having voltages higher than and lower than an output voltage to a load end. If one power source is failed, the other power source can still transfer power normally. Moreover, if an appropriate control circuit is matched, the currents and powers of the two input DC power sources can be accurately controlled to accomplish tracking operations of the maximum power of each power source. The power conversion system can be exactly simplified to accomplish the effects of enhanced efficiency and lowered cost and also have the advantage of simultaneous transmission of power from two voltage sources to the load end.