afrooster Posted October 30, 2009 Share Posted October 30, 2009 I'm trying to find any information that might verify that the C-130's original electrical design was meant to be DC only. Also does anyone know why definitavel that they went the AC and DC route? I remember an instructor at LRAFB telling me that the C-130 was meant to be DC only but can't remember why it was or why for sure they changed it. Quote Link to comment Share on other sites More sharing options...
tinyclark Posted October 30, 2009 Share Posted October 30, 2009 (edited) I may not know what the hell I am talking about, but that wouldn't have worked IMHO. All nav aids have to use AC for the synchro outputs to indicators. There always has to be a reference waveform. This would involve having to use many small inverters, or dynamotors, which was what was used on the old ARN14 VOR system. Any electronic system, such as HF, Doppler and RADAR, needing high voltage would need AC to work with step up transformers. DC fuel pumps wouldn't bode well, what with all the sparking from the brushes going on. The DC generators would have to be HUGE. I remember some older cars with generators, and they were big and damn heavy. They use 400Hz instead of 60Hz to keep the generator size down. The aircraft batteries would probably take up a pallet position due to the current draw of all systems if they were DC. Wiring would have had to be a larger gauge, and on and on and on. So, I'm picking up a slight to heavy scent of bovine excrement from this story that instructor gave you. Edited October 30, 2009 by tinyclark Quote Link to comment Share on other sites More sharing options...
donwon Posted October 30, 2009 Share Posted October 30, 2009 We had a mess of inverters and transformers under the flt. deck. We could us the DC power cord from the md3 to refuel.it only had 3 cords. The AC cord had 6 cords and we had to use it for the fuel pumps. We could use AC only but had to use the battery to get AC to run on the plane. The DC was to hold the relays in for the AC to run something. When de fueling we were suppose to use the AC and DC power cords both from the md3. I don't remember why the AC had the 6 cords unless it was 3 phase. I do remember some of the planes haveing an ac generator on only the #2 and 3 engines. For some reason I had thought they had a smaller dc generator on all 4 engines. I am only talking about the A models. I remember haveing to take generators off the #2 or 3 engines and put a plate over the hole where it had fit on the engine but never on the #1 and 4 engines. I think I been out 43 or 44 years next month. Nov 18 66. You can bet I got some CRS going on. Tiny was the AC 3 phase on the A,s? Quote Link to comment Share on other sites More sharing options...
afrooster Posted October 30, 2009 Author Share Posted October 30, 2009 thanks tiny, man i knew something stunk in denmark.....just couldn't deny what i heard though. seems inconsequential but i understand the adbantages of ac power, but what are the advantages of DC power? why use both? Quote Link to comment Share on other sites More sharing options...
stoney Posted October 31, 2009 Share Posted October 31, 2009 The A was a DC acft. 4 DC generators, 1 on each engine and 2 AC generators, one on #2 & #3. 13 DC busses with the "I" strip (isolated DC bus being the most important, located on 245). The B on up became AC acft. Stoney Quote Link to comment Share on other sites More sharing options...
bischoffm Posted October 31, 2009 Share Posted October 31, 2009 I testing my memory now, but you could refuel the A model with AC power (if you did not have a DC cart, by holding in the hot day start button and switching on TR 1 and 2 then releasing the hot day start button, RIGHT!! Quote Link to comment Share on other sites More sharing options...
Steve1300 Posted October 31, 2009 Share Posted October 31, 2009 There was so much difference between the original "A" model and the "B" model that it could have been given a different name from "C-130." Many design changes happened, and the electric power scheme was only one of them. It was not a DC-only bird, but they sure focused on DC heavily in the original design. I am actually glad that I got to work on them. It makes me appreciate the current configuration. Quote Link to comment Share on other sites More sharing options...
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