Wednesday, March 9, 2011

the ever-popular "unavoidable delays"

Most projects are either on hold or simmering.  There is family drama occupying some of my time, and support for my wife some, and little left for hobbies.  I have good excuses, but they're none of your business.

I'll report again when I have something significant to talk about and some free time.

Meanwhile, I am puttering about doing little useful things around the shop such as painting Glyptal 1201 onto once-adjustable power resistors, turning them into higher-voltage non-adjustable resistors.

Don't get excited, they're wirewound so inductive as hell (not yet measured, I'll get around to it) and I haven't the faintest idea of their tolerance, but frankly my friends, I couldn't care less.  For this application - safety discharge current limiters - some inductance is welcome, and if they're +/- 20% on the resistance I'm happy.

This is for a safety grounding stick project. The idea being that you really (and I can't stress this enough) DO NOT want to ground out the "hot" part of a high voltage system after or during an electrocution incident with your grounded safety grounding stick... if the source you're about to touch it to has an ESR near zero and the capacity to source perhaps 300,000 amps into your ground lead.  Whoa.  Could be exciting.

So this safety "chicken stick", which will also be used during shut-down procedures, will be equipped with integral power resistors capable of dissipating 1kW continuously and many kilowatts in a single short pulse.  They'll be able to take a full (10kV) charge to zero (no, not allowing for dielectric absorption, astute students) in a few seconds whilst avoiding a great deal of noise, energetic photons, and coronary arrests.

The resistors were left over from the old ignitron triggering circuits in the pulser, and the Glyptal (which you should look up, it is extraordinary stuff) was left over from coating the secondary of my "Last Tesla Coil". (which isn't receiving any time either, boo hoo)

The chicken stick has now gone from convenient and easy to use but unsafe to ridiculous to use, but safe.  Oh well.  I'll be sure to post a pic when it's done.

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