| 摘要 |
1,183,703. Automatic voltage control. JOSEPH LUCAS (INDUSTRIES) Ltd. July 6, 1967 [July 8, 1966; July 18, 1966; Sept. 9, 1966], Nos.30721/66, 32123/66 and 40314/66. Heading G3R. A battery charging system for a road vehicle comprises; a generator 24, e.g. an alternator with a rectified output; a voltage regulator R, including n. p. n. transistors Fig. 1 (not shown), connected in series with a resistance 44, e.g. a warning lamp, across the battery 21, the regulator controlling in known manner the current flow through the generator field winding 31 so that the output voltage of the generator is maintained constant; an ignition switch 23 connected, in series with the electrical load 22 of the vehicle, across the series combination of regulator and resistance; a switch 43, e.g. the contacts of a relay 46, separate from but controlled by the ignition switch 23 for ensuring that the regulator dissipates power only when the ignition switch is closed; and a further switch 45, e.g. relay-operated contacts, operable when the generator is producing an output for effectively short-circuiting the resistance 44. In operation, when the ignition switch is closed and the generator starts up, the voltage regulator first is supplied from the battery 21 by way of the lamp 44 which is thus also energized; as soon as the generator produces an output, the switch 45 closes to short-circuit and extinguish the lamp 44, the field current then being no longer limited by the resistance of the lamp. In another embodiment Fig. 3 (not shown) the resistance 44 is constituted by a resistor and the switch 43 by a transistor, the generator-controlled switch being arranged to complete a circuit to a warning lamp through the ignition switch when the generator is not producing an output. A further embodiment, utilizing a regulator having p. n. p. transistors, is described with reference to Fig. 4 (not shown). |
