Water resistors and other Loads

[KB2WIG]

Back when I was a young JN, the schol put me in the industrial electricity lab to keep me out of trouble. While doing some experiments, we would use a water resistor for some of our load.  We was workin with DC rotary equiptment--  150VDC, 80A per unit. manual starters. adjustable ckt breakers... lots of laughs setting up the pretty Cu arc. Now that I have to PAY for my own toys, does anyone have any suggestions for testing HV power supplies.. I don't want to fire up my ART-13 withought testing the  B+ on something else... I dont want to series lamps if I dont gotta... Anyone got any comments/ideas?      klc

[WA1GFZ]

Put the supply on a variac and fuse and go for it.

[WBear2GCR]

Sorry, I gotta ask. What is a "water resistor" exactly??

Pure water happens to be an insulator. Add salt (etc.) and it becomes a weak conductor...

I'd been eyeing that title for three days now, finally I had to look, and ask!

     _-_-bear

But, yeah a variac, ammeter and voltmeter on the B+ is a good way to go - of course, if you have rectifier tubes, you'll perhaps want to make a provision to feed the primary of the B+ xfrmr from the variac, or else temporarily replace the rectifier tubes with solid state diodes...

[KB2WIG]

Thanks guys.....
      I guess i'll go with the variac and fuse route....I have some nice oil cans (23uF@4KV) and some 10uF@2KV. I wanted to try various configurations to get around 1.2KV for my project.  i guess i'll go the trial by fire routine..  I like to bake things before I set them into metal.
      I cant let the pure water thing go... Yes pure, non ionized water is an insulator. But, water is  amphiprotic- that is, water molecules  transfer protons between each other, which is results in H30+ and OH- ......  Which is a really, really really small  small shift to the left on the pH scale.....  Add some Beer and a discussion of acid rain and a Monty Pythin abuse/argument session devolves... Good for parties.... anyway,
       Water resistor.... I should have kept my mouth shut...... Picture a industrial mop bucket on weels made up of very thick bucket walls. Then picture a chain with a window weight looking electrode attached.  The bucket wall is ground and the window weight is attached via a conductor to the devices B+.  The water is distlled water with a chemical to act as an electrolyte. The chain part is attached to a 'crank' wich raises/lowers the electrode into the fluid, thereby varying the resistance..The electrolyte is generally a salt; maybee copper sulfate ( will not have much reaction with a copper conductor).  Gud for large loads...  The other types are used for High Voltage..... Tesla at Colorado type high voltages. they use long tubes filled with electrolyte....     

[NE4AM]

Hoo boy.  I had some experience with this years ago, testing a 12 KV, 100 KW shortwave modulator. (COMMERCIAL GEAR, NOT FOR HAM USE!)  Lessons learned:
#1.  All hardware in the water must be stainless steel, or else electrolysis will make short work of it!
#2.  Huge amounts of H2 and O2 _will_ be liberated.  You have the potential for a nasty explosion unless the H2 is dealt with properly!

Be careful, OM!