(no subject)

[meanfreepath]

When I took gen chem in college, because I hadn't done chemistry in a while, there was a period of several weeks where I broke a different thing in lab each week. It was mostly very minor stuff... things like glass stirring rods, but nothing expensive like a volumetric flask.

But I always figured I wouldn't break stuff in physics labs, and until today I generally haven't.

I just managed to blow out a brand-new wall-wort transformer. I think it may have been a bad solder joint leading to a loose wire that caused the short circuit... I was probing around with a DVM and suddenly there was an ominous spark. Granted, it's a $15 device, but now I'll have to order another one, and the purchasing office hates orders under $50.

Comments

[blaketh.livejournal.com]

Will you use a benchtop power supply until it arrives? (I am shivering as I type; the ocean was very cold.)

[meanfreepath.livejournal.com]

Yeah... hopefully there's one around. Our lab is short on electrical equipment.

[msarcher.livejournal.com]

Clearly you should throw a couple of extra items in the order...

[meanfreepath.livejournal.com]

Yeah... it's hard to do sometimes though. That is, it's not easy to think of things you may not need just then. Alternatively, one can in desperation just order large quantities of the thing you need. That is why there is a box of almost 100 fuses (the guy only needed one or two) sitting around the lab somewhere.

[trinfinity2001.livejournal.com]

Though i'll bet they hate, say, orders of $500 a lot more.

[meanfreepath.livejournal.com]

No, surprisingly, orders for large amounts of stuff aren't a problem. Of course, it's very easy to spend upwards of $500 on a single item. A nice Agilent/HP regulated DC power supply would cost around that much.

[sildra.livejournal.com]

For a nice power supply? That's pretty cheap. Our low-power power Kepco power supplies usually run well upwards of $1000 (we don't trust HP/Agilent on both stability and fast switching in the same power supply... one or the other, sure, depending on what it was made for, but only Kepco seems to be good at both, or so my advisor tells me).

[meanfreepath.livejournal.com]

*shrugs* You probably know better than I do... the one good power supply in our lab is an HP/Agilent. The electronics shop also stocks them, and they are used in the undergrad electronics lab, perhaps because Paul Horowitz apparently likes that company. But honestly, you probably know better than I do.

[sildra.livejournal.com]

Power supplies are sometimes limiting factors in our experiments because they're so expensive (a really nice power supply can run well above $10,000, and that's still a low-voltage DC supply). My advisor met someone at DAMOP once who had the same experimental setup as me and had given up on it, because he wasn't willing to shell out the money for the power supply that could make it work. We usually pay about $1500 for our power supplies, used; they're about $3-4000 new, I think.

On the other hand, we need 0.1% precision with switching times in the 100 microsecond range.

pork barrel spending!

[olifhar.livejournal.com]

Eh, you've probably taken care of it at this point, but perhaps you should just order four of the transformers! Thus, you will have backups in case you decide to blow one again and the purchasing office won't mind as much. Bloated institutional spending!

I am trying in vain to funny here, though. Probably I would more like to say, we all make mistakes and break stuff. Intelligent people like you break small things that cost $15 and it's a hassle but in the end it's okay. Real dumbasses do stuff like breaking whole nations. I trust some people more with small things, details. Computers even. But Jerome, I'd trust you with big, important things more than a whole lot of people out there. Peace.