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Technical Description Accessories Ericsson Handheld Telephone 1341-B Vehicle Power Adaptor VP2000 Contents Introduction ___________________________________________ 3 Main Features _________________________________________ 3 Power Supply ____________________________________________ 3 Charging ________________________________________________ 5 Specifications_________________________________________ 6 Connectors and Signals ______________________________ 6 System Connector J1 ______________________________________ 6 Power Connector J2 _______________________________________ 7 Technical Description Accessories: VP2000 2 Technical Description Accessories: VP2000 Introduction The Vehicle Power Adaptor VP2000 is plugged into the 12 V cigarette lighter outlet and provides power to the telephone at the same time as it charges the telephone battery. The Vehicle Power Adaptor consists of three parts; the plug which contains the electronics, the coiled cord and the detachable connector part. Main Features Power Supply The logic in the telephone controls the power supply. The current values needed by the telephone in different situations, for example in standby or in transmission, are programmed and stored in the telephone. The VP2000 delivers two current levels only, 700 mA and 30 mA. These lev- els are pulsed during a 30 seconds period to enable any average level to be achieved. Every 30 second period begins with a 700 mA pulse and ends with a 30 mA pulse. The length of 700 mA pulse decides the average current. 3 Technical Description Accessories: VP2000 Examples: Standby: 700 mA for 4 seconds gives 4s / 30s x 700 = 93 mA Transmission: 700 mA for 25 seconds gives 25s / 30s x 700 = 583 mA The battery of the telephone takes care of the redundant current during the 700 mA part and support with extra current during the 30 mA part. This means a battery always has to be attached to the phone when it is connected to the Vehicle Power Adaptor. Note: To trickle-charge the battery the actual value of the current is set some mA higher than the current required. 4 Technical Description Accessories: VP2000 Charging The batteries used are of the type nickel metal hydride, NiMH. There are four contacts on the battery: plus, minus, T and K. The contact T is used for the temperature sensor. K is not used. When the telephone is connected to the charger and switched ON, the battery condition is analyzed. If charging is decided, 700 mA is delivered constantly. During the charging the voltage and the temperature increase and follow the curve