Abstract: An LC series resonant regulator is connected across the output of the inverter circuit of a static converter apparatus to vary the output voltage level as the inverter operating frequency varies from a preselected frequency at which the regulator circuit is tuned. The load is coupled across the capacitor element of the regulator and a level detector coupled across the load input. This detector registers variations of the input to the load from a predetermined desired level of load voltage and supplies a feedback signal, indicative of any detected variations, to the control circuit for the inverter circuit element. This control circuit is responsive to a feedback signal to vary the operating frequency of the static inverter so that the regulator varies the output voltage applied to the load to restore the desired voltage level.

Abstract: An air-conditioning system in which a static inverter is driven at a predetermined constant frequency during a normal service mode of vehicle operation to effect operation of the vehicle cooling and/or heating unit such as to maintain the interior temperature of the vehicle within a chosen comfort zone. During initial start-up, when the interior temperature reaches extreme proportions due to the vehicle sitting in the sun or cold, an abnormal service mode of operation is called for in which the static converter is driven at an increased frequency and voltage for a predetermined limited time to rapidly bring the interior temperature within the comfort zone. The so-called abnormal service mode of operation may be indicated manually by the train service personnel under extreme temperature conditions after the start-up period of abnormal service mode has expired. Also provided is a passenger load sensing arrangement to increase the ventilation capacity of the cooling unit fans when overcrowding exists.

Abstract: A high voltage power supply system for energizing a static inverter, in which an auxiliary circuit provides a source of reserve energy to sustain inverter operation during periods of power interruption. In the auxiliary circuit, there is provided a capacitance normally charged from the source of power (catenary) via a resistance whose ohmic value assures a slow rate of charge to avoid blowing the input fuse in the event of a short in the auxiliary circuit capacitance and to permit use of the desired capacitance with a reduced voltage rating. A diode arrangement statically connects the higher of the catenary voltage or the stored energy reserve of the auxiliary circuit to the inverter.

Abstract: A fluorescent lamp support assemblage comprising a printed circuit board on which is pre-mounted the electrical components comprising a converter or the like for supplying proper power to operate the vehicle lights and a sheet metal member cut and bent into a channel-shaped form. The printed board and a pair of fluorescent lamp holders are secured in place on the respective side walls and base of the channel-shaped member by snap inserting a plurality of tabs on the printed circuit board panel into conforming slots in the side walls in the case of the circuit board and by snap inserting the opposite edges of an opening in the base of the channel-shaped member into a notch formed in each side of the lamp holders in the latter case.