| 摘要 |
A safety circuit (201) for a rechargeable cell (202) includes an undervoltage circuit (203) having a reference voltage (210). The input of the safety circuit (201) is selectively coupled between the voltage of a rechargeable cell (202) and a scaled down voltage of the rechargeable cell (202). The scaled down voltage corresponds to a predetermined capacity threshold. A user or electronic device actuates a switch (211) that couples the scaled down voltage to the safety circuit (201). The safety circuit (201) compares this scaled down voltage to the reference voltage (210) of its undervoltage circuit (203). If the scaled down voltage is above the reference voltage (210), the safety circuit (201) causes a transistor (206, 207) coupled serially with the cell (202) to be on, or in a conductive state, so as to allow current to flow through a capacity indicator (208) like a LED. If the scaled down voltage is below the reference voltage (210), then the safety circuit (201) causes the transistor (206, 207) to enter a high impedance state, thereby turning the indicator (208) off. |
