US 2014/0112036 A1 · POWER SUPPLY WITH OUTPUT PROTECTION AND CONTROL METHOD OF THE POWER SUPPLY

Abstract

The present invention relates to a power supply with output protection and a control method of the power supply. The invention mainly provides a pre-protection value lower than a default over-current protection value. When a present output current of the power supply is higher than or equal to the pre-protection value and is lower than the over-current protection value, the method firstly determines whether the power supply has abnormal conditions. When the power supply has abnormal conditions, the method can automatically provide or stop providing a working voltage to a load. When the present output current is further higher than or equal to the over-current protection value, the method takes an over-current protection action. By multi-level monitoring of the current values, the invention properly provides an over-current protection.

Claims14

Dependent claims

A control method of a power supply, the control method comprising the steps of:

providing an over-current protection value;
setting at least one pre-protection value being lower than the over-current protection value;
acquiring a present output current of the power supply;
determining whether the present output current is higher than or equal to the pre-protection value;
taking an over-current protecting action when the present output current is higher than or equal to the over-current protection value;
executing a first temperature determination process when the present output current is between the pre-protection value and the over-current protection value;
stopping an output voltage of the power supply when a present temperature of the power supply is abnormal by executing the first temperature determination process;
and
returning to the step of acquiring the present output current of the power supply when the present temperature of the power supply is normal by executing the first temperature determination process.

6 more elements

A power supply with output protection, the power supply comprising:

a rectifier circuit having an AC input terminal and a DC output terminal;
a PFC circuit having:
an input terminal connected to the DC output terminal of the rectifier circuit;
and
an output terminal;
a transformer having:
a primary side connected to the output terminal of the PFC circuit;
and
a secondary side;
an output circuit having:
an input terminal connected to the secondary side of the transformer;
and
an output terminal generating an output current;
a power switch device connected to the primary side of the transformer;
a PWM controller having:
at least one feedback input terminal;
and
a PWM signal output terminal connected to the power switch device for activating or inactivating the power switch device;
a microcontroller providing an over-current protection value and having an output current detection terminal, an alarm signal output terminal, a temperature signal input terminal, a latch signal input terminal and an output terminal, wherein the output terminal is connected to the feedback input terminal of the PWM controller;
a current detector having:
an input terminal connected to the output terminal of the output circuit;
and
an output terminal connected to the output current detection terminal of the microcontroller;
a lead detection circuit having:
a current signal input terminal connected to the output terminal of the current detector;
and
a latch signal output terminal connected to the latch signal input terminal of the microcontroller;
the lead detection circuit providing a pre-protection value and sending an alarm signal to the microcontroller when the output current of the output circuit reaches the over-current protection value, wherein the pre-protection value is lower than the over-current protection value;
and
a temperature detector connected to the temperature signal input terminal of the microcontroller.

27 more elements

Dependencies are inferred from the claim text.

Power supply with output protection and control method of the power supply

Life of this patent

Power supply with output protection and control method of the power supply

Life of this patent

Abstract

Claims14