kevin gilmore

WARNING TO ALL... http://gilmore.chem.northwestern.edu/dsc_2288.jpg The one on the left is real, the one on the right is fake, and breaks down at 200 volts. birgir and i got nailed on this, about half of the ones i bought were fake, and most of birgir's (if not all of them) are fake. Evidently there are also 2sa1486 fakes out there, i don't have any pictures of the fakes. Get yourself one of these http://www.ebay.com/itm/DY294-Transistor-Semiconductor-Parameter-Tester-Meter-/120755611246?pt=LH_DefaultDomain_0&hash=item1c1d98666e and test all the high voltage transistors before you put them in. This includes the T2 !

RK50 to control the attenuator. I kind of like that idea. The RK50 should be available in mono, so not as much as you might think. Stereo with dual shafts might be nice, one for volume, the other for balance. The digital encoders are a way better idea.

schematics for the dynamic boards. I think these are the ones that match the boards. http://gilmore.chem....fetschembal.pdf http://gilmore.chem....ipowerschem.pdf http://gilmore.chem.northwestern.edu/dynahiver2a.pdf

mcm electronics had real 2sk216, but now out of stock, 81 days delivery. they don't stock the 2sj79

need version with 2 pots, one for volume, the other for balance.

kyocera damascus ceramic 8.25 inch sashimi knife and kyocera damascus ceramic pocket knife. kyocera damascus 6.25 inch santoku and battery powered diamond wheel should be here tomorrow. pictures tomorrow.

And the problem is that the current waveform before the diodes is nothing like a sine wave. So the RMS value which is what all transformer manufacturers want you to specify does not exist. Why these companies cannot understand full wave diode bridge into capacitor of specific value, and that into a resistive load of specific value i don't know. And even if you tell them the number of turns on the primary, and wire size, and the number of turns on the secondary and wire size, they insist on arguing with you.

Too specific for most people. Besides which, cast does not really work the way you might think it does. Raw current out of a dac is unusable with even a few feet of cable, and then there are all the offsets that need to be controlled.

by the way, although i have not tested it yet, it should be compatible with the amb/linuxworks LCDuino thing. you can tighten up on the timing because the relays on my board move at least twice as fast. kerry's code is ultra simple and works great, additions would be necessary to go balanced if you actually want the balance control function. My new NMR install starts 8/22/2011, about 3 weeks early, so i'm not going to have much time for a while on the ultra fancy 4Dsystems thing. Bonus points for the first person to do a 3 knob volume control software. (.5db, 5 db, 50db) (or some such whacky stacked dial thing)

600 volts DC unregulated under load. Which translates to 430 VRMS under load. Turning that into a transformer that works can be more problematic than you might think.

the new power supply board also has a voltage multiplier so you can build it with lower voltage primaries for less heat. http://gilmore.chem.northwestern.edu/kgsshvps8e.pdf

I got a better idea. Desolder the sockets. Go and get the teflon sockets. You can buy the cheaper version if you want. They fit fine as long as you get them all the way down on the board and level.

I gave 2 to justin and they work great for this. But you have to be careful which ones to pick. Some go to 3kv. And with those, a mistake can blow up everything. Also these power supplies have protection circuits that measure impedances to ground and also minimum and maximum current levels, so that is an issue. The computer controlled biorad units are sweet. Some units also monitor the special connectors that are plugged into them. Without those cables you might have to jury rig them to get the supplies to turn on. Remember that these things are designed to be used by biology people who have no brains and no respect for something that can generate 300 watts or more at up to 5kv. these are the good ones, i have a few http://cgi.ebay.com/BioRad-PowerPac-3000-Electrophoresis-Power-Supply-/110529882532?pt=LH_DefaultDomain_0&hash=item19bc1829a4 these are pure trash, stay away, lots of different versions of this under different names http://cgi.ebay.com/Life-Technologies-Gibco-Electrophoresis-Power-Supply-/270762844688?pt=LH_DefaultDomain_0&hash=item3f0ab92210 and this http://cgi.ebay.com/ELECTROPHORESIS-POWER-SUPPLY-BIORAD-MODEL-1420B-/310338137420?pt=LH_DefaultDomain_0&hash=item4841982d4c these are hard to fix if they do blow up, but seem pretty reliable http://cgi.ebay.com/LKB-Electrophoresis-Power-Supply-2301-Macrodrive1-/170673614011?pt=LH_DefaultDomain_0&hash=item27bcf0acbb

red mallee knob in progress http://gilmore.chem.northwestern.edu/rmallee1.jpg http://gilmore.chem.northwestern.edu/rmallee2.jpg http://gilmore.chem.northwestern.edu/rmallee3.jpg

originally it was actually part of the board. but that was when it was single sided and much longer. does not make sense to make the whole board 6 layers just for the attenuator, so its likely going to end up as a board of boards.

5 minute conversion to LP gas... So my old oven went to 450F. New oven goes to 550F, broils at 650F self cleans at 750F (not that i will ever broil in the house with the weber)

I think i have 5 of the amphenol stax jacks left. I will never use them, so if someone needs them let me know.

http://gilmore.chem.northwestern.edu/dsc_1981.jpg http://gilmore.chem.northwestern.edu/dsc_1983.jpg dishwasher is next

They are both part of the stax mafia.

The best solution for this is something texscan corp did about 25 years ago. series mosfet switch to parallel mosfet switch to ground, to series mosfet switch. Good for about 105 to 110 db when done this way.

Pretty sure justin is going to make a batch of the teflon jacks. I'm planning on making a small run of teflon plugs. Once i find suitable pins.

No one beats team stax mafia for speed, quality and accuracy NO ONE

sweet will drop this layout into the kgitsojc board when i finally decide what switching relays to use. Time for some fancy software.

For the kgsshv power supply, it sure looks like the bigger ones will fit on the small heatsinks. I'll measure later. For the T2, absolutely not, they have to be .5 wide.

Erwin from Australia just sent me a wonderful piece of very dense Red Mallee Birl. So i think i will make a few more knobs tomorrow