July 22, 201411 yr That said I have the newest onboard PCB's should anybody need some. Stunning boards. Petite next to the older Lil Knight PCBs.
July 22, 201411 yr For a 450V psu if using 2sa1486, do the unpopulated 270V zeners need to be shorted? No needs jumper @270V position.
July 22, 201411 yr Author Do not jumper the 270V zeners! either install them, or leave the slots empty.
July 22, 201411 yr that is how I build mine. How about MOSFETs all the way till the 4th stage, leaving the 2sc4686a in, and having the IXYS as CCS. https://docs.google.com/spreadsheet/ccc?key=0AoNVeoQi85GgdEFDQnc1aVZBdmNoc0o4WXczVGwxSVE#gid=0 Some of the EOL BJTs are getting real hard to find, and I am worried about getting fakes and having my amp blow up.
July 22, 201411 yr Author I think you have the mosfets and bipolars backwards. all the Motorola parts are current production. all of the ixys parts are current production
July 22, 201411 yr Sorry typo. I meant the BJTs are getting hard to find. For those using 115V, what's the max inrush current you have seen upon power on? I am trying to get a circuit breaker switch. Also, can I use the 2sc2632 from Panasonic (http://www.classiccmp.org/rtellason/transdata/2sc2632.pdf) to replace the 2sc2705? Edit: Nevermind I bought 20 2sc2705 from eBay just now. Hopefully it's not fake. What's the difference between 2SC2240BL and 2SC2240GR, apart from the DC current gain, hfe?
July 22, 201411 yr Stunning boards. Petite next to the older Lil Knight PCBs. Indeed they are. Granted this one doesn't have the IXYS CCS option, but it's still impressive how much size has been shaven off (while adding the servo no less).
July 22, 201411 yr Just so you know, there is an error on that board... The lower A970 is the wrong way around. Ohh and take care with that empty hole in the top center. Very easy to make that go all arcy sparky.
July 22, 201411 yr Thanks, I'll have to check which way I put them in when I get home. Guess it's a good thing I'm still waiting on the (2U/300mm depth/450mm width) enclosure for my new HV. Gonna be a tight fit (nothing like the tiny HV though), and hopefully nothing blows up.
July 22, 201411 yr I haven't fired one of these up yet so there might be more gremlins hiding somewhere. It was a bit of a challenge to make it this small in the first place and then add the servo...
July 22, 201411 yr Author on that version of the board, the A970 and mpsw56 are labeled backwards. The correct position is the a970's on the left and the mpsw56 on the right. latest board had the silkscreen right, consult that for more info.
July 22, 201411 yr Yep, had to flip the lower A970s. The other A970s were already in the left position. Just to be sure, is 100V rating enough for the .1uf caps for the servo?
July 23, 201411 yr Does this look genuine? http://www.ebay.com/itm/12pcs-Toshiba-New-Original-Genuine-2SC4686A-C4686A-transistor-TO220-/281367004966?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item4182c7c726#ht_1352wt_918 If I read right, that listing is for 12 pieces and not just 1? That is dirt cheap going to buy a mini stash. There are two versions of the 2SC2705 O and Y class, O has hfe 80-160 and Y is 120-240, does it matter either of which is used? Edited July 23, 201411 yr by DefQon
July 23, 201411 yr Yes this looks like 12 pieces. Thats why I ordered 48 pieces. Now let's just hope they are real.
July 23, 201411 yr Doesn't matter which 2705 you use. Yep, had to flip the lower A970s. The other A970s were already in the left position. Just to be sure, is 100V rating enough for the .1uf caps for the servo? P1080241s.jpg Ahh so that's what those look like when the max height of any component isn't equal to the terminal blocks...
July 23, 201411 yr What about the 1uF cap in the feedback loop of the OP 27 op amp, what rated voltage should I use? The lead spacing is 15mm. http://gilmore.chem.northwestern.edu/kgsshvproductiondual.pdf
July 23, 201411 yr I guess the lead spacing was made 3 times as wide as the one for the 0.1uF cap as it makes the tracing under the PCB easier. Sorry for sounding dumb, but I asked because there's not much reason to make the lead spacing that wide for a low voltage cap, film/ceramic.
July 23, 201411 yr Author for the servo cap you really want a film cap. which is why it is that big. ceramics as I have found out have real trouble as integration caps.
July 23, 201411 yr All of the film caps with a 15mm lead spacing have a 0.8 lead diameter, at least the ones I've searched for, which is too big for the onboard pcb holes. Nothing that a file can't fix, just thought I'd mention. Edited July 23, 201411 yr by johnwmclean
July 23, 201411 yr Oh you gotta be fucking kidding me, that listing just ended all sold out before I could buy some. Ffs
July 24, 201411 yr For the fuse, is 3.5A slow blow good for 240V, and for 100V/115V, is 5A slow blow OK? Or is the amperage too high? I read there were people having their 2A fuses burnt out on 240V. What about 3.15A for 240V, and 4A for 115V? If I am trying to push the current on the output stage to 8mA or 10mA, would that increase the power draw by a noticeable amount? I will also be having a 2 pole circuit breaker that is also a switch at the live and neutral.http://www.mouser.com/ProductDetail/TE-Connectivity-PB/W33-T2N1Q-5/?qs=sGAEpiMZZMvNllHT6Fj2fjyJLrUxEIJBwh69Ah0ZpOM%3d Edited July 24, 201411 yr by kh90123
July 24, 201411 yr Oh you gotta be fucking kidding me, that listing just ended all sold out before I could buy some. Ffs More listed now. //UFN
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