High-voltage coincidence

I’m in need of a high-voltage, low current DC power supply temporarily for an experiment in the lab, prices for these from the usual suppliers run into the hundreds of pounds. Given that all (all but the very best ones anyway) they consist of is a string of diodes and capacitors in a Cockcroft-Walton configuration, I decided to build one.

C-W generators are reasonably safe devices unlike their very similar cousins, the Marx generator. The voltage developed by the generator might be very high in both cases, but the C-W generator supplies very little current, whereas the Marx gen will deliver something more fatally akin to a lightning bolt. That’s not to say you can’t hurt or kill yourself with a C-W gen, just that you’ll have a bit of a harder time managing it. If you have an ioniser in your house, it will be very little more than a few stages of a CW gen and some resistors for further current limiting.

So, that’s the high-voltage, where does the coincidence come in? It happened that yesterday while flicking though my copy of the December CERN Courier, I spotted a feature on Cockcroft and Walton splitting the atom using equipment based around the generator bearing their name. I may going into the details of their achievement in another post, but for now a photo of them in their finery (and not just because I can then count this as an EDW post. Oh no…)


Ernest Walton, Ernest Rutherford and John Cockcroft.

Bullshit baffles brains?

The new job is going reasonably well, I’m not sure that I’m over-keen at being introduced to people as the solution to all their troubles, but I hope I can be useful.

Tomorrow I have to entertain, persuade and divert some industrial partner visitors. Progress on the project they are coming to see is pretty much non-existent and the person working on it is, rather conveniently, away from looking after her sick child…

Tomorrow I’ll probably quickly set up a laser and some optics to launch some light into the sensor to at least make it look plausible (it might even work…), but explain I can’t show any results yet because I don’t have the samples (this is true, I don’t even know what the samples are).

Hopefully a spot of hand waving and illusion will send them off thinking they’ve seen something great, after all we are supposed to know more about this side of the project than they are.

Of course if they send someone possessed of a clue, I’ll just explain the situation and pick their brains for some ideas.


I’ve often wondered just what my cats get up to when they shoot out of the house in the morning heading for parts local, but unknown.

I’ve pondered fitting them out with a camera to capture their day, but never done more then ponder it. A chap in America has taken the idea and made it work Projekte CatCam. The cat’s trip starts here.

Engineering I approve of.

Happiness is a warm gun hot soldering iron.

Things are getting along quite well in the new lab. Large pieces of aluminium have been turned into small pieces of aluminium (and a lot of swarf), spectrometers have been upgraded and calibrated, and I’ve just finished building some constant current regulators for low currents.

The current regulators don’t work how I thought they should, but they seem to work nontheless. I should try and work out what is or isn’t happening, so I have some idea why things are not how I planned them.