Parmar 1000W metal halide Ballast for US M47 lamps

this is a Type of ballast I have been looking for, for over 10 years now, and I finally managed to grab not only 1 but 2! just like buses you wait 10 years and a bunch come along at once! (im sure the postman must of loved me, seeing as i live up 3 stories and these weigh 15Kg each...)

this ballast is very rare and quite special in that its a Ballast designed to run off a British 240V 50Hz mains supply but is for running US spec M47 1000W Metal halide lamps, lamps which to run with a Choke type ballast would require 400V Mains

its also compatible with British 400/415V 1000W mercury lamps, US H36 1000W mercury lamps, 1000W Thorn MBI lamps, and with 2 in parallel you can even run up 2000W Metal halide and mercury Lamps which normally ask for a 400V choke :D (this is why I bought 2) which means I can run up quite a range of lamps which I could not run up before :)

also,

when I got the Ballasts I thought it was a CWA ballast however

I was doing some testing with the ballasts and I noticed changing the capacitor value does not affect lamp current much, which if this was a CWA ballast should change the lamp current.

which makes me think that this is not actually a CWA Ballast, I think it may be some sort of HX style autotransformer ballast with the capacitor on the high voltage side of the auto transformer part of the ballast acting as a simple PFC capacitor correcting the power factor of the actual Ballast/choke part of this ballast so the auto-transformer part of the ballast can be made smaller since the current draw from the choke part will be less. and this is why there has to be a capacitor as without it, the power factor is not corrected and the auto transformer part would get overloaded.

I know the Thorn 1500W MBIL 240V step up transformer and 415V choke setup works in the same manner (ie requiring a capacitor otherwise the step-up autotransformer gets overloaded)

overall im quite ecstatic to have finally acquired such a ballast :) (even if I had to put my self into debt a little to get them LOL)