Power circuit, power recovery control circuit and method

Abstract

The invention discloses a power supply circuit, a power supply recovery control circuit and a method. A sampling circuit of the power supply recovery control circuit samples the output of the AC / DC power supply during the AC / DC power failure recovery process, and the power supply recovery control circuit controls the power supply recovery control circuit. When the circuit judges that the output voltage of the AC / DC power supply is lower than the output voltage of the current backup power supply according to the sampling result, the output voltage set by the AC / DC power supply is set to a target voltage value greater than the output voltage of the backup power supply (such as a battery). In this way, it can ensure that the output voltage Vout of the power supply is established normally after a short-term power failure of the system, thereby realizing the seamless switching between the backup battery and the AC / DC power supply to the power supply of the system during the recovery process of the AC / DC power failure. Compared with the existing oring circuit control method, the solution provided by the embodiment of the present invention is simpler, the cost is relatively lower, and the efficiency of the power supply is not significantly affected.

Description

technical field [0001] The present invention relates to the field of power supplies, in particular to a power supply circuit, a power supply recovery control circuit and a method. Background technique [0002] Some communication systems for AC / DC communication power applications, such as switches, need to be equipped with batteries in some application scenarios to meet the requirement that a short-term power outage does not affect certain services of the system. On these systems, the charge and discharge management circuit of the battery can be integrated within the communication power supply or within the system, such as figure 1 shown. figure 1 In this system configuration, the output of the power supply is directly connected to the DC bus of the system. When the mains power is cut off, the charging management circuit in the system receives the AC power failure alarm signal sent by the AC / DC power supply (hereinafter referred to as the power supply). , and then the contr...

AI Technical Summary

Problems solved by technology

If there is no Oring circuit at the output of the power supply, then when the mains power is restored, the PWM control chip inside the power supply starts to power on and work, and the control loop of the power supply detects that the output of the power supply has a voltage (that is, the battery voltage), and it is higher than the power supply itself. If the output voltage of the power supply is high, then the PWM chip of the power supply will no longer be driven, resulting in the failure of the Vout voltage of the power supply itself to be established.

In this case, even if S1 is disconnected with a delay, the system will still be powered off for a short time because the output voltage of the power supply cannot be established immediately.

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