| 摘要 |
This invention pertains to portable battery-pack power supplies for use in devices which must be operated between an upper voltage and a lower voltage limit. The battery pack is comprised of a main power supply and a reserve power supply. The reserve power supply is switched into series connection with the main power supply when said main power supply is discharged to the lower voltage limit. Means are provided for ensuring that only the initial power supply is switched into the circuit after fresh cells are installed in the battery pack. |
