| 摘要 |
A mobile telephone includes a built-in torch 6 or siren. Control circuitry 16 integrated into the mobile telephone circuitry limits the power being supplied to the torch 6 or siren. The control circuitry acts to limit the duration of the supply of current and also inhibits the supply of power when a battery condition monitor determines that the battery charge has fallen below a minimum level. A floating circuit is provided to switch the light on and off at a predetermined rate. |
