Battery charger having sensing wire and relay to connect/disconnect charger to mains power supply dependent if charger is connected to battery

摘要

A battery charger 1 has a sensing lead 2 and a connector 3 which is connected to a device 4 which is to have a battery therein charged. A mains supply isolating relay 5 may be energised by connecting said lead 3 to said device 4 thereby allowing mains supply to connect to enter said charger. Removal of said lead de-energises said relay and shuts off the mains power to said charger, thus the device does not draw a standby current. A manual override button 11 may be provided to allow the mains current to be supplied across the relay and hence to the charger in the event that the secondary battery 11 may be missing or not having sufficient power. A blocking diode 13 and indicating LED 12 may be provided.