Approach for generation of power failure warning signal to maximize useable hold-up time with AC/DC rectifiers
First Claim
1. A method of generating a power failure warning signal, the method comprises:
- a. monitoring a bus voltage of a power supply unit;
b. adjusting a power failure warning voltage threshold value according to a varying load condition of a load coupled to an output of the power supply unit, wherein adjusting the power failure warning threshold value comprises determining a bus voltage drop rate and setting the power failure warning voltage threshold value according to the bus voltage drop rate to allow a minimum time period between generating the power failure warning signal and powering off the power supply unit to prepare for power shutoff; and
c. generating the power failure warning signal when the bus voltage drops to the power failure warning voltage threshold value.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of optimally generating a power failure warning (PFW) signal has been disclosed here in such a manner that adjusts timing of PFW signal generation according to load conditions in case of input AC voltage loss. A PFW voltage threshold value can be set at a lower value under light load conditions and at a higher value under heavy load conditions. PFW signal generation can also be triggered by a timing mechanism that is set when a bus voltage drops to a voltage threshold value. A countdown time of the timing mechanism is set according to a determined bus voltage drop rate. In this manner, issuance of the PFW signal is delayed for lighter load conditions and the power supply unit is capable of extending normal operation under lighter load conditions before the PFW signal is issued.
-
Citations
14 Claims
-
1. A method of generating a power failure warning signal, the method comprises:
- a. monitoring a bus voltage of a power supply unit;
b. adjusting a power failure warning voltage threshold value according to a varying load condition of a load coupled to an output of the power supply unit, wherein adjusting the power failure warning threshold value comprises determining a bus voltage drop rate and setting the power failure warning voltage threshold value according to the bus voltage drop rate to allow a minimum time period between generating the power failure warning signal and powering off the power supply unit to prepare for power shutoff; and
c. generating the power failure warning signal when the bus voltage drops to the power failure warning voltage threshold value.
- a. monitoring a bus voltage of a power supply unit;
-
2. A method of generating a power failure warning signal, the method comprises:
- a. setting a power shutoff voltage threshold value;
b. setting a minimum time period to prepare for power shutoff;
c. measuring a bus voltage within a power supply unit;
d. determining a bus voltage drop rate;
e. determining when a power failure warning signal is to be generated according to the power shutoff voltage threshold value, the minimum time period to prepare for power shutoff and the bus voltage drop rate; and
f. generating the power failure warning signal. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9)
- a. setting a power shutoff voltage threshold value;
-
10. A method of generating a power failure warning signal, the method comprises:
- a. setting a power shutoff voltage threshold value;
b. setting a minimum time period to prepare for power shutoff;
c. receiving a load condition corresponding to a load coupled to an output of a power supply unit;
d. using a look-up table to determine a power failure warning voltage threshold value according to the power shutoff voltage threshold value, the minimum time period to prepare for power shutoff and the received load condition; and
f. generating a power failure warning signal upon a bus voltage dropping to the power failure warning voltage threshold value. - View Dependent Claims (11)
- a. setting a power shutoff voltage threshold value;
-
12. A processing device for generating a power failure warning signal, the device comprises:
- a. means for setting a power shutoff voltage threshold value;
b. means for setting a minimum time period to prepare for power shutoff;
c. means for measuring a bus voltage within a power supply unit;
d. means for determining a bus voltage drop rate;
e. means for determining when a power failure warning signal is to be generated according to the power shutoff voltage threshold value, the minimum time period to prepare for power shutoff and the bus voltage drop rate; and
f. means for generating the power failure warning signal. - View Dependent Claims (13, 14)
- a. means for setting a power shutoff voltage threshold value;
Specification