Power supply
First Claim
1. A power supply unit having a power source consisting of a lithium-ion cell, an overdischarge detection circuit for detecting overdischarge of the power source, and an overcurrent detection circuit for detecting overcurrent, further comprising:
- a delay circuit that delays outputs of the overdischarge detection circuit and the overcurrent detection circuit,wherein the delay circuit provides different delay times between when overdischarge is detected and when overcurrent is detected.
2 Assignments
0 Petitions
Accused Products
Abstract
A power supply unit has an overdischarge detection circuit for detecting overdischarge of a power source, an overcurrent detection circuit for detecting overcurrent, and a stopping circuit for stopping overdischarge or overcurrent in accordance with an overdischarge detection signal or an overcurrent detection signal. The power supply unit is further provided with a delay circuit to prevent the overdischarge detection circuit and the overcurrent detection circuit from being activated erroneously by external noises. This delay circuit provides a variable delay time so that the delay time will be longer when overdischarge is detected than when overcurrent is detected. This makes it possible to stop overdischarge and overcurrent without fail.
24 Citations
6 Claims
-
1. A power supply unit having a power source consisting of a lithium-ion cell, an overdischarge detection circuit for detecting overdischarge of the power source, and an overcurrent detection circuit for detecting overcurrent, further comprising:
-
a delay circuit that delays outputs of the overdischarge detection circuit and the overcurrent detection circuit, wherein the delay circuit provides different delay times between when overdischarge is detected and when overcurrent is detected. - View Dependent Claims (2)
-
-
3. A power supply unit comprising:
-
a power source consisting of a charge-and-discharge battery; a first power source monitoring circuit for monitoring a voltage of the power source in order to output an overdischarge detection signal when the voltage drops below a predetermined voltage; a second power source monitoring circuit for monitoring a current outputted from the power source in order to output an overcurrent detection signal when the current exceeds a predetermined current; a delay circuit of a variable delay-time type that delays the overdischarge detection signal and the overcurrent detection signal using a longer delay time when overdischarge is detected than when overcurrent is detected; stopping means for stopping discharging of the power source; and a control circuit for controlling the stopping means in accordance with an output of the delay circuit. - View Dependent Claims (4, 5, 6)
-
Specification