Abstract: Systems and methods for implementing a safety circuit in charging devices are disclosed. In an exemplary embodiment, a method may include closing a latch to stop delivery of a charging current to a battery when voltage produced by the battery indicates that the battery is non-rechargeable. The method may also include dropping a threshold from an initial value for the voltage produced by the battery to a baseline value so that the latch remains closed even if the voltage produced by the non-rechargeable battery drops below the initial value of the threshold. The method may also include resetting the latch each time a battery is connected to the charging device.

Abstract: Systems and methods for implementing a safety circuit in charging devices are disclosed. In an exemplary embodiment, a method may include closing a latch to stop delivery of a charging current to a battery when voltage produced by the battery indicates that the battery is non-rechargeable. The method may also include dropping a threshold from an initial value for the voltage produced by the battery to a baseline value so that the latch remains closed even if the voltage produced by the non-rechargeable battery drops below the initial value of the threshold. The method may also include resetting the latch each time a battery is connected to the charging device.

Abstract: A telecommunications apparatus is connectable to a line accessible by plural telephone numbers from the public switched telephone network (PSTN). The PSTN identifies which telephone number on the line is being called by applying to the line a distinctive ring cadence. The telecommunications apparatus includes a processor, an interface for connecting to the PSTN, a memory for storing a distinctive ring cadence learn procedure and a nonvolatile memory. The processor is responsive to actuation of the distinctive ring learn procedure to monitor a received ring cadence and to derive distinctive ring data indicating characteristics of the received ring cadence. The processor stores the distinctive ring data in the nonvolatile memory and thereafter responds to received ring cadences to derive ring data therefrom. That ring data is compared with the stored distinctive ring data and if a substantial match is determined, causes the telecommunications apparatus to respond to the ring data.