[Prev][Next][Index][Thread]

Re: Water rheostat?




From: 	Daryl P. Dacko[SMTP:mycrump-at-cris-dot-com]
Sent: 	Friday, September 05, 1997 5:19 AM
To: 	Tesla List
Subject: 	Re: Water rheostat?

At 10:30 PM 9/4/97 -0500, you wrote:

>I'm advised to buy a variac to smooth out my switch-on transients. But
>why not an electrolyte rheostat which is $100 or so cheaper? I
>visualize a PVC pot of salt water containing basically two wires, one
>with a well-insulated handle. Such rheostats were used for various
>purposes in Tesla's day. Even a small volume of water could absorb
>the waste heat of a brief startup.
>Can anyone tell my why this wouldn't be a good alternative?

Been there and done that, along with others on the list...

It works fine, but if not engineered properly can be quite dangerious.

The main problems are eliminating leakage current through the operator
and handling boilovers which happen quite suddenly ;'}

I would advise a container within a container, both much larger than
you think you need.

I, until very recently, never used a variac, just throwing the switch
and have had no troubles.

Myself, I think it's mostly for effect, the fiendish mad Tesla coiler
dramaticly (sp) cranking the Big Black Knob until lightning breaks out
across the lab ;'}

Of course, seeing a salt water resister boil over while under power is
pretty dramatic too, with the steam and froth shot through with sparks,
etc. ;'}

Be very safe if you try this, OK ?

Daryl