Direct current power supply device having an alarm provided for power failure under varying load conditions
First Claim
1. A DC power supply device operative to supply DC power to a load in response to an AC power source, said device comprising:
- AD/DC converting means connected to receive AC power from said AC power source for converting an AC current into a direct current;
power failure detecting means, responsive to said AC power source, for generating a power failure detection signal when a power failure has occurred in said AC power supply;
means for detecting a load current value at the output of said AC/DC converting means; and
alarm signal generating means responsive to said power failure detector signal and said detected load current value for outputting an alarm signal after a delay time determined in accordance with said detected load current value in such a way that said alarm signal is output immediately before said load current value decreases due to the power failure.
1 Assignment
0 Petitions
Accused Products
Abstract
A direct current power supply device which generates an alarm signal when a power failure occurs in an alternating current power supply connected as an input to the device. A power failure detector circuit is connected at the input of the device and signals the failure of the AC power supply. In order to compensate for different time delays in the fall of the DC output due to varying loads at the output of the device, a reset signal generating circuit is used which is controllable in accordance with the size of the load. The circuit receives as an input, a signal identifying a power failure from the power failure detector circuit and a signal identifying the load current value from a load current value detector circuit, connected between the load and the AC/DC converter. The reset signal generating circuit, using analog or digital components, will generate a reset signal at a timing determined by the size of the load.
-
Citations
13 Claims
-
1. A DC power supply device operative to supply DC power to a load in response to an AC power source, said device comprising:
-
AD/DC converting means connected to receive AC power from said AC power source for converting an AC current into a direct current; power failure detecting means, responsive to said AC power source, for generating a power failure detection signal when a power failure has occurred in said AC power supply; means for detecting a load current value at the output of said AC/DC converting means; and alarm signal generating means responsive to said power failure detector signal and said detected load current value for outputting an alarm signal after a delay time determined in accordance with said detected load current value in such a way that said alarm signal is output immediately before said load current value decreases due to the power failure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A DC power supply device operative in response to an AC power source to provide DC power to a load, said device comprising:
-
an AC/DC converter, connected to receive AC power from said AC power source, for converting an AC current into a direct current; and reset signal generating means, responsive to a failure of said AC power source and to a DC load current level produced by said AC/DC converter for outputting a reset signal after a delay time determined in accordance with said DC load current level in such a way that said reset signal is output immediately before said load current value decreases due to the power failure. - View Dependent Claims (11, 12, 13)
-
Specification