Discharge lamp voltage supply circuit - uses voltage multiplier common to phase with auto-transformer associated with this phase and supplying lamp groups

摘要

The improvements are designed for the three phase electrical supply to a group of sodium, mercury or iodide discharge lamps. The lamp supply system includes a voltage multiplier (2) which produces a voltage greater than the supply voltage for example 270 volts from normal voltages of 220. There is only one voltage multiplier for the whole lamp supply system. The lamps are connected in groups of five: each group is connected as follows. Between phases (P1) and (P2) whose voltage is not modified and to an auto-transformer (AB, A'B'). The autotransformers are connected to phase (P3) and to the connection(P'3) from the voltage multiplier (2). The phase voltage (P3) is not altered, but the voltage (P'3) is made greater than the available phase voltages (P1, P2, P3) by the multiplier (2). The autotransformer (AB) compensates for line volt drop so that it is possible to ensure the correct voltage at each lamp group and to reduce cable size.