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>1000VDC Power Supply Experience
- Thread starter THD+N
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Two words... Bleeder Resistors.
Friend had a 10KV Fluke regulated power supply.
Didn't work when he tested it, Sat on a shelf for 6 months.
Gets around to opening it up to troubleshoot, Next thing remembers is waking up on the floor.
Turns out that changing settings too fast burns out the "Bleeder resistors".
Next morning I find it on my porch with a note "Careful".
Bleeder Resistors are important life saving circuitry!
Some supplies have a switch on the case, When you open it up it places a short across the HV caps.
Careful...
Edit: The popular saying is, Not only will it kill you, But It will hurt the entire time...
Friend had a 10KV Fluke regulated power supply.
Didn't work when he tested it, Sat on a shelf for 6 months.
Gets around to opening it up to troubleshoot, Next thing remembers is waking up on the floor.
Turns out that changing settings too fast burns out the "Bleeder resistors".
Next morning I find it on my porch with a note "Careful".
Bleeder Resistors are important life saving circuitry!
Some supplies have a switch on the case, When you open it up it places a short across the HV caps.
Careful...
Edit: The popular saying is, Not only will it kill you, But It will hurt the entire time...
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Of course, ALL transformers and chokes must be rated for the appropriate working voltage (not hi-pot, obviously). Nebraska Surplus and Sales is a good source for old mil-spec and transmitting stuff. I used 600VDC wire with teflon sleeving over the PVC. Ceramic stand-offs and terminal strips. Appropriate spacing to avoid arcing. Can't remember what all else, it was over 20 years ago. ;-)
Are you thinking of building a big amp or a transmitter? These days, I'd look at solid-state for those types of applications.
However, the high-output SS amp's current will kill you just as fast as HV.
kcin
Well-Known Member
I have a 211 amp that operates around 1200v or so. More recently, I have been working with a pair of electrostatic Beveridge direct drive amps that operate +/- 3200v in the chassis.
Heavy respect is demanded. I had to redesign the the transformers for the Beveridge as HV had taken its toll on the design. More to be said if you're interested.
Heavy respect is demanded. I had to redesign the the transformers for the Beveridge as HV had taken its toll on the design. More to be said if you're interested.
Been repairing electrostats for 35 years
Owned three sets of Beveridge's, Great stats.
5 pairs of Acoustat X's at 5,000 volts.
And Dayton Wrights that run at 10,000 volts. The supply weighs about 110 lbs.
There are so many pair's of exposed Oil capacitors that would probably end you pretty fast if you connected to them.
Almost forgot Hill Plasmatronics Helium Plasma tweeters, They are about 3,000 volts at a LOT of current...
Owned three sets of Beveridge's, Great stats.
5 pairs of Acoustat X's at 5,000 volts.
And Dayton Wrights that run at 10,000 volts. The supply weighs about 110 lbs.
There are so many pair's of exposed Oil capacitors that would probably end you pretty fast if you connected to them.
Almost forgot Hill Plasmatronics Helium Plasma tweeters, They are about 3,000 volts at a LOT of current...
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Have a few amps, 211, and a pair of 811-3' amps but I have not worked on them, but at work I helped a designer with a few proto type products, one that uses a cathode and anode to charge some chemicals in a solution to produce chlorine dioxide. We actually finished the prototypes and now have finished products to install in treatment plants where we generate the product which is harmless unlike the current method which requires bring in Clorine to treat the water. I used a DC power supply to provide 5000 volts DC to the tungsten rod which is the Anode I think and then the outer walls of the section where the fluid flows is charged with the negative lead the cathode. No special wire, just standard 600 v stranded.
We are working at producing a methane generator now, It uses two 5000-volt DC power supplies, and another 9000-volt power supply. I have no problem wiring them when the time comes, but I won't get to close while operating them when powered up.
I have wired a lot of high voltage stuff and one common practice that is required many times is for me to use a calibrated megger meter and meg all the wires, prior and after installation, to insure all integrity of the insolation of my wire and is documented.
We are working at producing a methane generator now, It uses two 5000-volt DC power supplies, and another 9000-volt power supply. I have no problem wiring them when the time comes, but I won't get to close while operating them when powered up.
I have wired a lot of high voltage stuff and one common practice that is required many times is for me to use a calibrated megger meter and meg all the wires, prior and after installation, to insure all integrity of the insolation of my wire and is documented.
I built dual mono 211 amps about 25 years ago. I was curious about how other DIY builders went about dealing with high voltage and precautions taken. It is a subject rarely discussed and if more information was available, I think more DIY amp builders might not shy away from a 211 or 845 amp due to >1000V power supply.
I read through an old ARRL book prior to my build and it is/was a great resource for good information on high voltage power supplies. 1000VDC~1200VDC is fairly easy to do with off the shelf parts. Over 1500VDC and you will more than likely have to use more specialized parts and that will drive up the cost significantly.
I have bleeder/equalizing resistors across my stacked caps in the power supply, so they are doing double duty. These resistors also make it easy to take a high voltage reading without exceeding my multimeter DC voltage limit. Most standard DMM's go up to 1000VDC. I fried my first meter thinking 1100VDC would be OK.
Years ago, I started to investigate/collect parts/build a Tesla Coil, but never finished. I would like to finish that one day.
My 211s operate at 1,050VDC. I used Teflon wire and also Teflon spaghetti in the high voltage areas. The main rectifier is a FWB with all the parts on FR4, so no problem there.
I was a ham for many years, and the difference between building a transmitter using +750V, or a linear amplifier running 3KV or 4KV was huge. Somewhere in there, probably around 1200V to 1500V, is where the architecture takes a big step and you start using lots of porcelain.
Jack
I was a ham for many years, and the difference between building a transmitter using +750V, or a linear amplifier running 3KV or 4KV was huge. Somewhere in there, probably around 1200V to 1500V, is where the architecture takes a big step and you start using lots of porcelain.
Jack
AK member @Maxamillion made a killer pair of tube amps that use 833 tubes. Looks like he used some special porcelain bases to help prevent any hi voltage arching. Maybe he can chime in with his suggestions for special handling.
Maxamillion
Super Member
My 833C mono amps build is documented here if you're interested:
The Midlife Crisis - My 833C Amp Build
-My wife, upon seeing the 833C triodes in person - "That's not an amp, that's a Midlife Crisis!" -My reply, "Hey, it's cheaper than a Corvette..." So was born my 833C SET monoblock project. The 833C is a ruggedized version of the 833A, with thick graphite plates capable of 400W dissipation...
2300V on the plates, at 160mA.
