GB645188A - Installation for the generation of electric current, with a dynamo supplying a battery with direct current, and utilization circuits for direct current and alternating current - Google Patents

Abstract

645,188. Electricity supply; automatic voltage control systems. ELECTROM. July 29, 1947, No. 20518. Convention date, Aug. 5, 1946. [Class 38 (iv)] Boosting by dynamo-electric machines; systems depending on two or more sources; ; variable-speed generators, with.-In a system in which constant voltage D.C. load circuits 16, 18 are supplied either from a constant voltage dynamo 1 through a cut-out 23, or from a battery 12 through a booster generator 9 excited by differential windings 10, 11 connected respectively across the battery and load circuit with the current in one winding regulated according to the voltage of the load circuit, an A.C. output circuit 27 of constant voltage is derived from slip-rings 24, provided on the booster motor 7, connected to points equidistant on the motor armature which is connected across the load circuit supply leads. Whilst the battery is charged the carbon pile 14 of a voltage regulator 13, included in the circuit of winding 11, is maintained at maximum resistance value, so that as the battery voltage increases the excitation of coil 10 increases, resulting in increase in charging current. When the load circuit is supplied from the battery, the voltage across winding 10 decreases, and winding 11 under the control of regulator 13 increases the booster voltage in order to maintain the voltage of the D.C. load circuit constant. The booster motor which is started when the cut-out or the load circuit switches 21, 22 are closed, has a resistance 19 included in the armature circuit, which is short-circuited when the voltage across the armature attains a predetermined value. The slip-rings 24 may be connected to the load circuit through a step-up delta/star transformer 25, 26 which may supply discharge lamps. According to the Specification as open to inspection under Sect. 91 the booster motor may be connected across the battery, in which case an additional field winding connected across the booster generator assists the winding 8 whilst the battery is being charged and opposed whilst the battery is being discharged, also the resistance 14 may be short-circuited by a contact when the cut-out 23 closes. This subject-matter does not appear in the Specification as accepted.