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Onelasttime
Junior Member Username: Onelasttime
Post Number: 30 Registered: 8-2011
| Posted on Wednesday, August 17, 2011 - 1:05 am: |
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Ok if I understand thing right the high voltage models as in 1500+ volts are going to be ac in and ac out correct? So I would need to use cap's and diodes to simulate DC to the Tubes and the other DC parts correct? I ask because I have been looking at them for an amp project. It is not a cost issue either because at these power levels they cost just as much as an E or C core conventional transformer AC/DC transformer. I am looking at packaging, reliability, leakage etc..... I am thinking 30-40lbs in size depending on how which company and product I go with. I also like that it is easier to switch them from 110 to 220 should I move back to Europe or if I should ever have 220 in my home. I have it out in my unheated Pole Barn for my welder since I have 120 @ 60CPS here it is actually 240 volts. Does anyone have a favorite supplier? I have looked at Petronix and Antec so far in the USA since I am in the USA I prefer to order domestic to keep shipping under control. |
Funtimebob
Intermediate Member Username: Funtimebob
Post Number: 294 Registered: 5-2002
| Posted on Wednesday, August 17, 2011 - 10:45 am: |
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All transformers work on some form of alternating current be it line level, AF, or RF. 1500 volts can kill so be extremely careful. Diodes don't simulate DC they "convert" AC to pulsating DC. The capacitors are used to smooth out the pulses. The amount of capacitance depends on the "ripple" factor. There is a formula to determine the amount of capacitance needed but I don't remember it off the top of my head. The amount of ripple "acceptable" depends on the usage of the amplifier (AM/CW) vs SSB. If I recall correctly the maximum recommended amount of ripple for a SSB capable amplifier is only 3 per cent. Since The capacitors in a high voltage supply hold a charge Bleeder resistors are used to "Drain" the capacitors. I don't know if it still holds true BUT for good regulation it was recommended that these resistors should be calculated to consume 10 percent of the total amperage of the supply. You DONT want to skimp on the power rating of these resistors. Peter Dahl was purchased by Harbach and is a good source of suitable transformers for amplifiers. Dyslexics of the world UNTIE! 73 De Bubba Honorary O.F.
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