Abstract: To provide an engine system with which in a case where a power supply voltage whose specification is to be changed is higher than an expected voltage, the specification of the power supply voltage from an alternating-current power supply can be changed at low cost without providing an additional transformer. An engine system 100 includes a transformer 130, a power receiving device 140, and a switcher 150, and switcher 150 connects a switching terminal 151 connected to one power receiving terminal 141 of the power receiving device 140 to either a first terminal 152 connected to one terminal 134 of a primary 131 or a second terminal 153 connected to a branch terminal 136. The engine system 100 is configured such that the other power receiving terminal 142 of the power receiving device 140 and the other terminal 135 of the primary 131 are connected and the primary 131 and an alternating-current power supply 200 are electrically connected.

Abstract: According to the present invention, even in the case of addition of a transformer for using an engine system with an AC power supply different from the expected voltage of an electrical device, there is substantially no change in the thermal balance in a package due to the presence or absence of the transformer. In the present invention, an engine 2 and an electrical device for driving the engine system are housed in a package 1. In order for a transformer 20 whose primary side is an AC power supply and whose secondary side is the expected voltage of the electrical device for driving the engine system to be housed in the package, an intake port, an exhaust port, and a ventilation fan for cooling the transformer are provided in a ventilation path that is independent from other devices.

Abstract: To provide a microphone unit for stereophonic recording capable of adjusting an intersecting angle of sound collecting axes in accordance with conditions without impairing directivity and sound quality of the microphone. Respective rotation bases (408, 508) are rotatable about a center axis with respect to mounting bases (404, 504), respectively, which are mounted to a main body (20) of a portable sound recorder (10) through respective brackets (402, 502). Respective top ends of respective knurls (414, 514) of leading ends of the respective rotation bases (408, 508) has a shape being cut to form an inclined surface from a radial direction, and respective microphones (418, 518) are retained so that diaphragms (420, 520) are in consonance with the cut surface.

Abstract: To provide a microphone unit for stereophonic recording capable of adjusting an intersecting angle of sound collecting axes in accordance with conditions without impairing directivity and sound quality of the microphone. Respective rotation bases (408, 508) are rotatable about a center axis with respect to mounting bases (404, 504), respectively, which are mounted to a main body (20) of a portable sound recorder (10) through respective brackets (402, 502). Respective top ends of respective knurls (414, 514) of leading ends of the respective rotation bases (408, 508) has a shape being cut to form an inclined surface from a radial direction, and respective microphones (418, 518) are retained so that diaphragms (420, 520) are in consonance with the cut surface.