Patent GB-250681-A (GB)
Title: Improvements in or relating to battery charging arrangements
IPC: H04M19/00
Filed: 1925-01-17
Abstract: 250,681. Automatic Telephone ManufacturingÀ Co., Ltd., (Automatic Electric Co.]. Jan. 17, 1925. Charging and discharging batteries.-An intermittently-used battery is automatically connected to charging means when put into use and a timing device ensures the continuance of charging for a predetermined period after the cessation of load. The invention is described as applied in an automatic telephone exchange. As shown in Fig. 1, the motor-generator MG is started by a switch S energized by a relay B when a call is made and a relay A energized. The switch S also prepares the circuit for a winding stopping MG, this circuit being eventually closed by a relay D under the control of a timing device T and a relay E also controlled by the timing device T. A relay C prepares a circuit for an impulse producer which drives the timing device T, this circuit being closed when the relay A is de-energized at the end of a calling period. The relay C also closes a circuit for an alarm device 14, 15, which is opened by the circuit breaker F when it has connected the battery and motor generator in parallel. On failure of the charging means the attendant cuts out a counter-cell P which is installed to permit charging without excessive voltage on the bus-bars G, H. The impulse producer comprises two thermal switches T, H in cascade, the time intervals of each being adjustable and the eventual closure of the contact 4 of the second energizing a motor-magnet propelling the wipers 1, 2 of the timing device T one step and operating a switch 30 which starts a fresh cycle. When the wiper 2 reaches contact 31 relay E is energized and a circuit prepared for relay D which is closed when contact 32 is reached, the motor-generator being thereby stopped and disconnected from the battery. On the occurrence of a calling period during the progress of the extended charging period the relay A will interrupt the current supply to the thermal switches and the next charging period will be reduced to an extent corresponding to the distance through which the timing device has moved, should the contact 31 not have been reached. Should the wiper have passed contact 31 then the subsequent charging period is prolonged. The period of charging may be varied by setting back the contact 31 or by adjusting the thermal switches. In the modification shown in Fig. 2 the motor generator 170 is put on charge by relays 102, 104 and coil 241 of switch 240, all energized by the closing of switch 196 on origination of a call. The battery 165 is also connected to the release equipment at 116 and the circuit of an alarm 152, 153, is closed at 115, this circuit being opened by the circuit breaker 111 when the generator is connected to the battery. A maintaining circuit for relay 102 passes through a relay 103 which becomes energized by the opening of switch 196 when calls cease. This energizes an impulse producer 109, 110 and the holding and operating coils of a timing device 200. A pin 204 on the timing device de-energizes relays 102, 103 at the end of the predetermined charge period and the timing device is reset. A relay 105 is then energized and the motor-generator disconnected by coil 242. The battery is also disconnected from the release equipment at 116. Recommencement of calling during the extended charging period causes the resetting of the timing device 200 by short circuiting the relay 103 at 196. The operation of the release equipment closes the switch 191 each time a call is cleared and the relay 106 energizes a meter coil 113 and through relay 108, a timing device 220 and the impulse producer 109. 110. The timing device advances an arm 226 which eventually opens at 225 a short circuit on a relav 107 which closes the circuit of an alarm 150, 151 and resets the timing device. 'The setting of the impulse producer and of the adjustable arm 226 determine the alarm period. 'Thus should the release equipment not function within a predetermined period after the cessation of calls the continuation of the load upon the battery is signalled. The load itself is cut off at the switch 116 when the timing device 200 has operated. The impulse producer 109, 110 comprises a spring 139, carrying an adjustable weight, which is set into vibration by the armature 138 of the relay 110, and when vibrations have ceased, the high impedance relay 109 becomes energized. This short circuits the relay 110 de-energizing also 109 and commencing a fresh cycle. Each energization of 109 sends an impulse by closing switch 136.