发明名称 |
Power supply circuit |
摘要 |
Disclosed is a power supply circuit of an electric device. The power supply circuit comprises a power source configured to output a power source voltage; a power source voltage detecting circuit configured to detect the power source voltage, and to output a first voltage control signal; a leading edge delay circuit configured to receive the first voltage control signal, and to output a second voltage control signal; an electronic switch connected in series between the power source and the load, configured to turn on or turn off power supply from the power source to the load; and a slow turn-on circuit configured to receive the second voltage control signal. |
申请公布号 |
US9046902(B2) |
申请公布日期 |
2015.06.02 |
申请号 |
US201314024804 |
申请日期 |
2013.09.12 |
申请人 |
Ricoh Company, Ltd. |
发明人 |
Chen Zefu |
分类号 |
H02M3/155;G05F5/00;H03K17/28 |
主分类号 |
H02M3/155 |
代理机构 |
Harness, Dickey & Pierce, P.L.C. |
代理人 |
Harness, Dickey & Pierce, P.L.C. |
主权项 |
1. A power supply circuit of an electric device, comprising:
a power source configured to output a power source voltage by which direct current is provided to a load; a power source voltage detecting circuit configured to detect the power source voltage, and to output a first voltage control signal whose leading edge corresponds to turn-on of the power source and whose trailing edge corresponds to turn-off of the power source; a leading edge delay circuit configured to receive the first voltage control signal, and to output a second voltage control signal whose leading edge is delayed by a predetermined time period relative to the leading edge of the first voltage control signal and whose trailing edge coincides with the trailing edge of the first voltage control signal; an electronic switch connected in series between the power source and the load, configured to turn on or turn off power supply from the power source to the load; and a slow turn-on circuit configured to receive the second voltage control signal, wherein, the slow turn-on circuit outputs, to the electronic switch, a switch voltage signal whose leading edge is used to control turn-on of the electronic switch and whose trailing edge is used to control turn-off of the electronic switch; a start time of the leading edge of the switch voltage signal coincides with a start time of the leading edge of the second voltage control signal, but a rate of change of the leading edge of the switch voltage signal is slower than a rate of change of the leading edge of the second voltage control signal, so that when the power source is turned on, a current flowing through the electronic switch is low enough to not be able to ruin a component through which the current flows; and the trailing edge of the switch voltage signal coincides with the trailing edge of the second voltage control signal. |
地址 |
Tokyo JP |