| 摘要 |
<p>1283927 Switching systems JOSEPH LUCAS (INDUSTRIES) Ltd 29 Oct 1969 [11 Nov 1968] 53232/68 Heading H2H In an electrical system for a road vehicle, a plurality of loads are controlled by respective switches. The closure of a switch causes the energization of two or more feed lines associated with that particular switch, and results in power being supplied to the respective load. In the system shown, loads L1-L5 are each connected in series with contacts C1-C5 to a battery supply line 12. The contacts are controlled by relay coils R1-R5, and are associated with main switches S1-S5 serially connected with a relay coil 15 which is normally energized to hold open a contact 14. In operation, one of the main switches, say S1, is moved to make contact with a pair of diodes connected to two feed lines, in this case 21 and 22. The coil 15 is thus de-energized, contact 14 closes, and current flows into resistors 41-45 in series with the coils R1-R5. Each resistor is also connected through a pair of parallel diodes and resistors 31-36 to earth, and in the ease of resistors 42-45, sufficient current flows to earth to prevent energization of the relay coils R2-R5. However, both diodes associated with resistor 41 are back-biased due to the connection of feed lines 21, 22 to the battery, so that the current in the resistor 41 flows wholly through the coil R1, closes contact C1 and energizes the load L1. The relays are of the type which remain operative until re-energized, when their contacts open again. The system shown includes six feed lines 21-26 so that up to fifteen loads can be controlled by choosing all possible combinations of pairs of lines.</p> |
