Power supply circuit and electronic device

A power supply circuit for supplying a direct current voltage generated based on an alternating voltage to be supplied via a power supply switch, comprising:

• a first power supply system for supplying a first voltage to a first circuit unit;
• and
• a second power supply system for supplying a higher second voltage than said first voltage to a second circuit unit giving a lighter load comparing with a load by said first circuit unit,
• said second power supply system including
• a regulator supplied with power from said second power supply;
• a reverse flow preventing diode arranged between an output portion of the regulator and said first circuit unit;
• and
• a feedback circuit for detecting a voltage to be applied to said first circuit unit and feeding back the detected voltage to said regulator, and
• said regulator adjusting an output voltage thereof based on the voltage detected by said feedback circuit, so that a voltage to be applied to said first circuit unit for a predetermined time after said power supply switch is turned off becomes approximately said first voltage.