June 26, 201510 yr 442K: 71-RN60D4423F Not the Carbon? Kevin understood me, major brain fart time... I should try to sleep some more but there really is no time. I did mean the Carbon.
June 26, 201510 yr Author new from the ground up symmetrical carbon in progress http://gilmore.chem.northwestern.edu/kgsshvcarbonv2.jpg 6 x 4.35 inches
June 26, 201510 yr That's looking impressively small. A depth of 4.35 inches implies a horizontal mounting unless on goes for at least a 3U case. But horizonal is probably the easier and better way anyway. I like it very much. Does it make sence to use mpsa06 and pzta06 on the same board? May I also suggest to add descriptions for the trim pots on the silk screen? Makes it easier.. Edited June 26, 201510 yr by insanity
June 26, 201510 yr Author updated the picture, please check against schematic for accuracy. the board is now 5.65 x 4.35 inches the idea is to stuff this into the pesante 2U box. just fits. With the new power supply 6 x 6.5 inches, 2 amp channels on one heatsink, and the power supply on the other. leaves more than 5 inches x 6 inches for the transformer. now to find some r-core transformers. single box, all standard parts Edited June 26, 201510 yr by kevin gilmore
June 26, 201510 yr Is the via above the left hand current source too close to the bracket, considering its on the top of the board?
June 26, 201510 yr Author fixed that could make it one board that would be 11.125 x 4.35 just to make it easier
June 26, 201510 yr one board may have to advantage of less cables, if possible to modify accordingly. but i think for shipping and practicality reasons 2 boards are probably better Edited June 26, 201510 yr by insanity
June 26, 201510 yr Author it would be the same number of cables. both boards would fit on one angle bracket with .5 spacing final board size 5.45 x 4.2 inches so the boards fit side by side. here is what it would look like in the Dissipante 02/300N 2U 4mm BLACK (360mm wide x 300mm deep internal) http://gilmore.chem.northwestern.edu/kgsshvcarbonchassis.jpg for the amp boards, you can lift off the bottom of the chassis by .8 inches then put the power input block on the bottom of the board. would make for a very pretty wiring job. Edited June 26, 201510 yr by kevin gilmore
June 27, 201510 yr Looks good. I guess I'm not the only one wanting to build this. Just out of curiosity. What is the reason why we use 4 separate rectifier diodes instead of one bridge as in the kgst supply?
June 27, 201510 yr So you'd want a larger cap? Why? Looks good. I guess I'm not the only one wanting to build this. Just out of curiosity. What is the reason why we use 4 separate rectifier diodes instead of one bridge as in the kgst supply? Because those diodes are SiC and there aren't any SiC bridge rectifiers.
June 27, 201510 yr I just noticed that the two .47uf/50V disc caps don't seem to have the same lead spacing.
June 27, 201510 yr Author fixed everything I know of, same names have a look also the stax mafia are starting to use these http://www.digikey.com/product-detail/en/THINC22-TO220-16-11.4-5.8-0.3/1168-1953-ND/3878142 on the dn2540 and the power diodes would like to find that part at mouser, but can't yet (works well on the kgst cascode board) Edited June 27, 201510 yr by kevin gilmore
June 27, 201510 yr oh good should work on the exposed tab lm7*15 parts too also today is the time to find out what all the TKD pot fuss is about
June 27, 201510 yr I was just thinking about the orientation of the boards in the case. How much heat is generated by the PSU board? Is it similar to 1 amp board or significantly more/less?. From eyeballing it would just fit to put the psu and one amp board on one side and the other amp board on the other side. This would give us more space in the middle/front part of the case. But I don't if this is a good idea if it results in significantly different temperature of both heatsinks/amp boards. I am dreaming about an rk50 in the middle behind the front panel... Furthermore I have a question about the shoulder washers used with the bigger ceramic pad for the to247. Which ones do you use? The holes of the bigger ceramic pads are also a bit bigger. Edited June 27, 201510 yr by insanity
June 27, 201510 yr This looks really nice! The main reason to use this over the Carbon servo board from earlier is size, right? A few small requests for the silkscreen to make it completely self-explanatory: 1. Add voltage ratings for all caps that don't have them (1uF by the servo, 5pF, .47uF at the bottom). 2. Add an OR next to the LSK389/K170 spot, like on the KGST. 3. Labels for the the 100ohm trimpots. Not sure what they do.
June 27, 201510 yr Author added labels to the silkscreen and updated the zip file the original board is 6.28 x 3.37 inches and won't fit in a standard chassis with the power supply the new board is 5.45 x 4.2 inches the new layout is much tighter, shorter lengths and the two output sections are absolutely identical. I have an alternate version of the power supply split into two pieces each 3 x 6.5 inches so you could mount the power supplies vertically, one per heatsink, and one amp channel per heatsink Edited June 27, 201510 yr by kevin gilmore
June 27, 201510 yr Author http://gilmore.chem.northwestern.edu/boards/kgsshvpssicfetsinglenewleft.zip http://gilmore.chem.northwestern.edu/boards/kgsshvpssicfetsinglenewright.zip
June 27, 201510 yr The amp boards look great and I really like the idea of the split power supply. Certainly makes case selection more flexible. It seems like it might even be possible to partially overlap the amp and PSU and go for a shorter but taller case.
June 27, 201510 yr For the SiC PSU, what's the voltage value for the 47uf caps near the top? Since the old zener string is gone, how exactly is the output voltage (400V vs 450V) determined?
June 27, 201510 yr Author change the value of the 2 resistors in series on the other side of the reference. the 47uf are tantalum capacitors, and 35v is fine. just in case the zener has to go up to 24v
June 27, 201510 yr Thanks kevin. Would 500V caps work for 450V operation or should 550V ones go in anyway?
June 27, 201510 yr Author I would definitely go with the 550v caps. depends on the voltage range of your power. if you go with standard voltage +/-5% you might squeeze in to the 500v but if its standard voltage +/-10%, that's pushing it.
June 27, 201510 yr change the value of the 2 resistors in series on the other side of the reference. the 47uf are tantalum capacitors, and 35v is fine. just in case the zener has to go up to 24v might be a stupid question, but don't you need the 20k resistor to maintain a drop of 10V? something like (Vcc-10V)/0,5mA = total value of two resistors in series ? so in case one cannot get the resistor values needed, the 20k can be changed a bit up/down as long as there are 10V across ...right?
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