摘要:
This specification discloses an overcurrent protective circuit for detecting an overcurrent flowing through an electrostatic self-turn-off device and suppressing the overcurrent.The overcurrent protective circuit according to the present invention comprises a power source for supplying a driving voltage to the electrostatic self-turn-off device to turn on the device, a switching circuit for performing on-off control of the driving voltage to provide a driving signal to the self-turn-off device, and a circuit for detecting the voltage of the driving control terminal and holding the potential of the driving control terminal below the driving voltage in response to the detected voltage reaching a predetermined value.
摘要:
When actuating again in induction motor rotating inertially by applying power to the induction motor from an inverter capable of changing both of its output frequency and output voltage, the power is once supplied to the induction motor to increase the residual voltage if the residual voltage of the induction motor is not sufficient, and the frequency of an initial impressed voltage that is in agreement with the rotating speed of the induction motor is determined.
摘要:
The invention provides a technique and a product in which for a frequency converter supplying electric power to, for example, a motor, a downsizing, lightening or the like of the frequency converter is realized while providing a filter apparatus reducing electromagnetic noises and the like. The filter apparatus reducing electromagnetic noises and the like is provided near a main circuit terminal board of the frequency converter, and the filter apparatus is connected directly to a main circuit terminal as a wiring drawing portion of the frequency converter. Part of a housing of the frequency converter and part of a filter housing are fitted to each other to fix the filter housing to the frequency converter.
摘要:
A power converter connected to a wiring drawing portion of a frequency converter, said filter apparatus including: a condenser element having an electronic part having an insulator as a dielectric material held between conductor plates; a sealing agent sealing said condenser element; a filter circuit comprising said condenser element; a connection conductor establishing wiring connections of said filter circuit; and a filter housing supporting said sealing agent.
摘要:
A filter apparatus connected to a wiring drawing portion of a frequency converter, said filter apparatus including: a condenser element having an electronic part having an insulator as a dielectric material held between conductor plates; a sealing agent sealing said condenser element; a filter circuit comprising said condenser element; a connection conductor establishing wiring connections of said filter circuit; and a filter housing supporting said sealing agent wherein said filter apparatus is fixed to said frequency converter based on a positioning portion provided in part of the housing of said frequency converter.
摘要:
An electric circuit module comprising: an electric device comprising an electric circuit to serve for passage and interruption of electric current, a packing material packing the electric circuit and a plurality of wiring members to electrically connect the electric circuit with an external circuit; and a heat sink to radiate heat from the electric device. The electric circuit module includes a fixture to fix the heat sink and the electric device together so that a heat radiating surface of the electric device comes into contact with the heat sink. The fixture is formed with a recess to accommodate therein a part of the electric device so that the heat radiating surface of the electric device is exposed from the fixture. When the electric device is fixed to the heat sink by the fixture, the heat radiating surface comes into contact with the heat sink.
摘要:
An object of the present invention is to lower the voltage applied to the starting resistor of the starting circuit in a switching power supply circuit to reduce the power loss especially when the receiving voltage is high and thereby provide a small and inexpensive switching power supply circuit.According to the present invention, a switching power supply circuit comprises: a DC voltage section having two or more capacitors connected in series; and a PWM control circuit for receiving DC power supply from the DC voltage section and performing switching control on a primary side of a transformer in order for the switching power supply circuit to output a DC voltage of different voltage specifications; wherein the starting resistor for the PWM control circuit is connected to a connection point of the capacitors.
摘要:
Measures are provided to prevent temperature rise caused by that heat generated from power elements, which is radiated inside a housing.In a housing comprising a radiating section and a cooling fan, a guide is provided on a part of the housing to be made longer a predetermined value than the radiating section. When the cooling fan performs forced cooling through the guide, gases heated by a substrate that generates much heat are prevented from flowing onto a substrate that generates comparatively less heat, to heat the substrate that generates comparatively less heat. Therefore, for example, the substrate that generates much heat is arranged in a position nearer to the cooling fan than the substrate that generates comparatively less heat. Alternatively, the substrate that generates much heat is arranged in a position nearer to the intake face than the substrate that generates comparatively less heat. By providing the guide on the housing, an existing fan can radiate heat from the substrate that generates much heat, the substrate that generates comparatively less heat, etc., thereby enabling reduction in temperature rise.
摘要:
Measures are provided to prevent temperature rise caused by that heat generated from power elements, which is radiated inside a housing. In a housing comprising a radiating section and a cooling fan, a guide is provided on a part of the housing to be made longer a predetermined value than the radiating section. When the cooling fan performs forced cooling through the guide, gases heated by a substrate that generates much heat are prevented from flowing onto a substrate that generates comparatively less heat, to heat the substrate that generates comparatively less heat. Therefore, for example, the substrate that generates much heat is arranged in a position nearer to the cooling fan than the substrate that generates comparatively less heat. Alternatively, the substrate that generates much heat is arranged in a position nearer to the intake face than the substrate that generates comparatively less heat. By providing the guide on the housing, an existing fan can radiate heat from the substrate that generates much heat, the substrate that generates comparatively less heat, etc., thereby enabling reduction in temperature rise.
摘要:
An inverter apparatus using a microcomputer control system suitable for use in driving an ac rotary electric machine is concerned. The inverter apparatus includes a device for detecting an output current or an output voltage of the inverter apparatus or a control signal supplied to the inverter apparatus and, from the detected result, detecting an output frequency of the inverter apparatus and a switch structure having memory function by means of change-over and selection of lines for holding data for setting therein an upper limit of the output frequency of the inverter apparatus in hardware manner. Thus, the device for detecting the output frequency of the inverter apparatus produces the output frequency of the inverter apparatus and the switch structure produces the exact upper limit of the output frequency which is not influenced by noise or the like. The comparison therebetween can suppress the output frequency of the inverter apparatus to the upper limit always reliably without permanent change due to noise or the like and a fear of changing data so that occurrence of over-rotational speed operation of the driven ac rotary electric machine can be prevented sufficiently.