| US 7,586,727 B2 | ||
| Inrush current limiting switching circuit for power supply | ||
| Tsuyoshi Yamashita, Anjo (Japan) | ||
| Assigned to DENSO Corporation, Kariya (Japan) | ||
| Filed on Sep. 29, 2006, as Appl. No. 11/529,545. | ||
| Prior Publication US 2007/0091528 A1, Apr. 26, 2007 | ||
| Int. Cl. H02H 9/08 (2006.01); H02B 1/24 (2006.01) | ||
| U.S. Cl. 361—93.9 [307/131; 323/908] | 12 Claims |
| 1. A switching circuit for selectively connecting or disconnecting a first power supply to an electrical load having an electrostatic
capacitance, comprising:
a first switch selectively connecting or disconnecting the first power supply to the electrical load;
an inrush current limiting circuit connected in parallel with the first switch and including a second switch and a resistor,
the resistor serially connected to the second switch, the second switch selectively connecting or disconnecting the first
power supply and the electrical load, and the second switch being on before the first switch is turned on;
a diode serially connected to the second switch and connected to the first power supply in a forward direction thereof, the
diode sensing an electric current passing through the second switch when both the first and second switches are in an off
state; and
a monitoring circuit monitoring the electric current when the second switch is in an off state.
|