[arriflex]

I recently acquired a working 1978 Boss4 Series 1 Bridgeport with the Vram head. My shop runs on 480V 3phase, and I can't stand the thought of throwing out a perfectly good power supply when I should be able to use it!
In looking over the schematics for my Bridgeport, I find a power supply style that I am not familiar with. In searching the Yahoo cam group, as well as CNCzone, I was not able to find anyone who had described using the existing three phase supply during a retrofit; but much of that I liken to most of the users' desire to switch to single phase given the opportunity.
In any case, this supply appears to have some sort of voltage following or normalizing type circuit to balance the three phases in DC. I have seen the secondary transformers described as both bucking transformers and line reactors, neither of which I believe are accurate based on the scematic. I could be completely off base, correct me if I'm wrong. The truth is, I'm not against building a new supply, but my dad is not for throwing away such "perfectly good iron!" and I really don't care about speed for this machine. So the question is really whether or not it is worth it to simply tap the supply in a similar fashion to the original Bridgeport drivers (see attached schematic), or to yank it and build anew? If I do use the existing supply, where should I tap in to best preserve the new Gecko 202 drivers and my old Superior motors?
Thanks to all who reply!
edgar

[keebler303]

You have a dc side fuse for each axis in the control cabinet. it would be ideal to tap into the power just downstream of the fuse. they are FU12, 13, 14 on your schematic.
Matt

[jderou]

I had the same question about those devices here: http://www.cnczone.com/forums/showthread.php?t=25109
turns out they are saturatable core reactors. I have been considering doing something similar with mine. You will have to keep the ACC card though.

[arriflex]

Thanks, as you described in your other post, and I was replied to at the Yahoo Cam group, the SX1 is a saturable core reactor. I appreciate the link, it helped bring clarity to this circuit as basically allowing the motors and drivers to sit in a lower voltage (9-12Vdc) standby state until motion is called for. When motion is called for, the 56Vdc supply saturates the reactors and brings the voltage back up for use. What a ingenious method of taking care of the motors and drives, not to mention helping keep the electrical and cooling bills down in a shop!
Too bad I am going to yank it all out! For a hobbyist, it just isn't necessary, and I am going to clean up and simplify by going to a simple supply.

Does anyone know how many amps the single phase 110v/40v T6 transformer is? I could just use that for a 56Vdc supply for now if it is big enough.
edgar