Power supply having a reduced number of switching elements
First Claim
1. A system comprising:
- a power outage detection circuit which detects that an output voltage of a DC voltage source has been lowered, and outputs a power outage signal;
a battery charger, directly coupled to the charing and discharging path to a load, comprising a switching element which adjusts the output voltage generated by the DC voltage source, in performing a switching operation, and is set to be ON KEEP in response to the power outage signal; and
a battery which is charged by the battery charger and supplies the electric power to the load when the switching element is set to be ON KEEP;
wherein the switching element comprises a high side FET and a low side FET which operate in a synchronous rectification method, and on condition that the low side FET is off, the high side FET is set to be ON KEEP in response to the power outage signal.
2 Assignments
0 Petitions
Accused Products
Abstract
There is provided a power supply capable of reducing switching elements. In a power supply, an AC/DC adapter 121 supplies electric power to a load 125 and a battery charger 122. The battery charger comprises a high side FET 102 and a low side FET 103 which operate according to a synchronous rectification method, and charges batteries 108 and 109. When a commercial power supply fails, a power outage detection circuit provided in the battery charger detects the power outage, and outputs a power outage signal. The battery charger which has received the power outage signal sets the high side FET to be ON KEEP. A discharge current from the battery flows via a discharge path 119. This enables a reduction in the number of FETs in comparison with other power supplies.
-
Citations
14 Claims
-
1. A system comprising:
-
a power outage detection circuit which detects that an output voltage of a DC voltage source has been lowered, and outputs a power outage signal; a battery charger, directly coupled to the charing and discharging path to a load, comprising a switching element which adjusts the output voltage generated by the DC voltage source, in performing a switching operation, and is set to be ON KEEP in response to the power outage signal; and a battery which is charged by the battery charger and supplies the electric power to the load when the switching element is set to be ON KEEP; wherein the switching element comprises a high side FET and a low side FET which operate in a synchronous rectification method, and on condition that the low side FET is off, the high side FET is set to be ON KEEP in response to the power outage signal. - View Dependent Claims (2, 3)
-
-
4. An apparatus comprising:
-
a power outage detection circuit which detects that an output voltage of a DC voltage source has been lowered, and outputs a power outage signal; a battery charger, directly coupled to the charing and discharging path to a load, including a switching element comprising a high side FET and a low side FET which operate in a synchronous rectification method, and the high side FET is set to be ON KEEP in response to the power outage signal; a first charge/discharge path connected to the output of the battery charger; a second charge/discharge path connected to the output of the battery charger; a first battery connected to the first charge/discharge path; and a second battery connected to the second charge/discharge path. - View Dependent Claims (5, 6)
-
-
7. A system comprising:
-
an electronic device; a power outage detection circuit which detects that an output voltage of a DC voltage source has been lowered, and outputs a power outage signal; a battery charger, directly coupled to the charing and discharging path to a load, comprising a switching element which adjusts the output voltage generated by the DC voltage source, in performing a switching operation, and is set to be ON KEEP in response to the power outage signal; and a battery which is charged by the battery charger and supplies the electric power to the load when the switching element is set to be ON KEEP; wherein the switching element comprises a high side FET and a low side FET which operate in a synchronous rectification method, and on condition that the low side FET is off, the high side FET is set to be ON KEEP in response to the power outage signal. - View Dependent Claims (8, 9)
-
-
10. An apparatus comprising:
-
an electronic device; a power outage detection circuit which detects that an output voltage of a DC voltage source has been lowered, and outputs a power outage signal; a battery charger, directly coupled to the charing and discharging path to a load, including a switching element comprising a high side FET and a low side FET which operate in a synchronous rectification method, and the high side FET is set to be ON KEEP in response to the power outage signal; a first charge/discharge path connected to the output of the battery charger; a second charge/discharge path connected to the output of the battery charger; a first battery connected to the first charge/discharge path; and a second battery connected to the second charge/discharge path. - View Dependent Claims (11, 12, 13, 14)
-
Specification