sorenb Posted August 24, 2017 Report Share Posted August 24, 2017 1 Quote Link to comment Share on other sites More sharing options...
Whitigir Posted August 24, 2017 Report Share Posted August 24, 2017 (edited) Lol, don't worry about formula, I just looked up for directions Edited August 24, 2017 by Whitigir Quote Link to comment Share on other sites More sharing options...
wink Posted August 25, 2017 Report Share Posted August 25, 2017 (edited) thats nothing, 0 factorial, so 0! is equal to 1 only because if it wasn't it would **** up every other rule of math Edited August 25, 2017 by wink Quote Link to comment Share on other sites More sharing options...
gepardcv Posted August 31, 2017 Report Share Posted August 31, 2017 I ordered the Phoenix "PT 1,5" series terminal blocks which we discussed earlier. While it's nice that they have plastic along the bottoms, I'm not convinced they would help prevent arcing if a trace passes beneath the attached wire. (1) There is still no plastic right where the trace would run. (2) There is no plastic directly beneath the wire attachment. It's beyond me why there just isn't a fully-enclosed plastic housing here. Maybe it's another Phoenix part number which I haven't found yet. Photo attached. Quote Link to comment Share on other sites More sharing options...
mypasswordis Posted August 31, 2017 Report Share Posted August 31, 2017 Probably because the electrical conductivity of air is still less than that of the dieletric material. Moral of the story is just use less solder, added bonus you run out of solder less quickly. Quote Link to comment Share on other sites More sharing options...
johnwmclean Posted August 31, 2017 Report Share Posted August 31, 2017 http://au.mouser.com/ProductDetail/Phoenix-Contact/1790539/?qs=MfVUZiz0PxbRlZTU%2bIaPbA%3d%3d 1 Quote Link to comment Share on other sites More sharing options...
chinsettawong Posted August 31, 2017 Report Share Posted August 31, 2017 (edited) You might consider putting a thick coating of clear nail polish over the copper trace. It's a very good insulator. Edited August 31, 2017 by chinsettawong Change wordings 1 Quote Link to comment Share on other sites More sharing options...
Pars Posted August 31, 2017 Report Share Posted August 31, 2017 Or something like MG Corona Dope might help? 1 Quote Link to comment Share on other sites More sharing options...
wink Posted August 31, 2017 Report Share Posted August 31, 2017 Some kapton would work too.... 2 Quote Link to comment Share on other sites More sharing options...
cloudbp Posted September 5, 2017 Report Share Posted September 5, 2017 hi all im new to this DIY scene and looking forward to building this wonderful amp going to build a 450V version of KGSSHV carbon other than setting GRLV to 15V and GRHV to 450V and amp to 20ma output, is there anything else that i need to look out for? btw i saw a few build in this thread that have the 110V to 230V board, can share the board with me? thanks to kelvin and all for the awesome people here and of course the amp designs Quote Link to comment Share on other sites More sharing options...
johnwmclean Posted September 5, 2017 Report Share Posted September 5, 2017 Those voltage converter boards were Spritzers, I’m pretty confident he doesn’t offer them any longer. Quote Link to comment Share on other sites More sharing options...
tomoki Posted September 15, 2017 Report Share Posted September 15, 2017 hi all, im new to this DIY scene but i got a problem with the HV board. the 20K ohm resistor is kept burnt even both the M1090S are checked as broken and replaced a new one. Any body can give me some advise to fix this issue? It was burnt even in 450V no load conidition. Quote Link to comment Share on other sites More sharing options...
Pars Posted September 15, 2017 Report Share Posted September 15, 2017 There are so many things wrong with what is in that pic... what a fucked up build! Angle bracket appears to be shorting the green resistor to the fight for starters. Attention to detail is a prerequisite for building this kind of equipment. Quote Link to comment Share on other sites More sharing options...
tomoki Posted September 15, 2017 Report Share Posted September 15, 2017 3 minutes ago, Pars said: There are so many things wrong with what is in that pic... what a fucked up build! Angle bracket appears to be shorting the green resistor to the fight for starters. Attention to detail is a prerequisite for building this kind of equipment. Thx for comment. Originally the angle bracket is not shorted with the resistor, it is just because the M1090S mica set and the screw are taken out. The time I power the board this angle bracket are screwed in tight without short upload a photo again to avoid mis-leading Quote Link to comment Share on other sites More sharing options...
mypasswordis Posted September 15, 2017 Report Share Posted September 15, 2017 Obvious thing to do is check if the 20k resistor is shorting to something, particularly ground or something that is near ground. Why does it look like your input cap is about 5 meters long? Quote Link to comment Share on other sites More sharing options...
tomoki Posted September 15, 2017 Report Share Posted September 15, 2017 9 minutes ago, mypasswordis said: Obvious thing to do is check if the 20k resistor is shorting to something, particularly ground or something that is near ground. Why does it look like your input cap is about 5 meters long? Thx for the comment, confirmed the 20K resistor is not shorted. Quote Link to comment Share on other sites More sharing options...
congo5 Posted September 15, 2017 Report Share Posted September 15, 2017 (edited) that 20k is connected to ground, or in this case negative rail how much voltage is on input? what value are resistor dividers, voltage? 390k+390k=400v picture kinda small, can't see too much are the 390k resistors 390R? if those 390k where 0 ohms that would give you 8W across your R7 20K resistor Edited September 15, 2017 by congo5 Quote Link to comment Share on other sites More sharing options...
tomoki Posted September 15, 2017 Report Share Posted September 15, 2017 1 hour ago, congo5 said: that 20k is connected to ground, or in this case negative rail how much voltage is on input? what value are resistor dividers, voltage? 390k+390k=400v picture kinda small, can't see too much are the 390k resistors 390R? if those 390k where 0 ohms that would give you 8W across your R7 20K resistor Thanks for your comment. The input voltage is 360VAC and suppose the output shall be 400VAC Those 2 390K resistors are replaced to the 442K resistor I atttached the photo again Quote Link to comment Share on other sites More sharing options...
sorenb Posted September 15, 2017 Report Share Posted September 15, 2017 (edited) Quote Often it can be helpful to work at lower voltages when trouble shooting. Paralleling the high resistor in the probe string to get the circuit in action at a lower output DC. If regulation doesn't work for some reason and things go bad it usually isn't really bad. Parallel the R8(2x 450k) with one ~100k (one across both) will provide some ~100VDC. Initial check: The CCS's Use a lab supply at some or battery ~15-20V, through a DMM at mA: put the (+) at the drain (middle leg) of the 10m90, and the (-) at the bottom of the CSS where R2(100) and R1(4k5) meets ...you should get ~2mA ....if you see much more, try replace the DN2540. Do the same at the other CSS: (+) to drain (middle leg) at the 10m90, and (-) at the bottom (pin 6 at the voltage reference) ...you should get ~1.3mA ...if not the 10m90 is probably damaged. When powering up the supply, hold the variac when you reach some ~40-50VDC output, and check: the pin6 of lt1021 against "ground" (pin4) ....you should see 10V ...if not, the lt1021 has probably gone south Before raising the VARIAC further: Attach a DMM across the 2k at the bottom of the cascoded CSS ... you should see ~0V (when at ~50VDC output) and only before regulation kicks in, the voltage jumps to some ~4V; it happens just before you reach the desired output voltage Attach a DMM across the 3k at the source leg of the output CSS (right most leg) ...should be some steady ~4V Original post Edited September 15, 2017 by sorenb 1 Quote Link to comment Share on other sites More sharing options...
MLA Posted September 15, 2017 Report Share Posted September 15, 2017 Sören's guide is excellent! Should get you on the right track. Also, I'd suggest checking the status of the BC557; they can handle max 45-50V across, so if the whole circuit has seen 360x 1.414 = 509V while something else is out of place they may be toast... 1 Quote Link to comment Share on other sites More sharing options...
Helium Posted September 15, 2017 Report Share Posted September 15, 2017 On 31.08.2017 at 3:16 AM, gepardcv said: I ordered the Phoenix "PT 1,5" series terminal blocks which we discussed earlier. While it's nice that they have plastic along the bottoms, I'm not convinced they would help prevent arcing if a trace passes beneath the attached wire. (1) There is still no plastic right where the trace would run. (2) There is no plastic directly beneath the wire attachment. It's beyond me why there just isn't a fully-enclosed plastic housing here. Maybe it's another Phoenix part number which I haven't found yet. Photo attached. Why do you guys always refer to 5-mm pitch connectors while the board has 5.08-mm pitch? Quote Link to comment Share on other sites More sharing options...
congo5 Posted September 15, 2017 Report Share Posted September 15, 2017 7 hours ago, tomoki said: Those 2 390K resistors are replaced to the 442K resistor I atttached the photo again much better photo's that 20k should never see hardly any wattage, something is bridged/blown, tracks,pins, transistors possible Q5 & Q8 direct short through all pins 1 Quote Link to comment Share on other sites More sharing options...
mwl168 Posted September 15, 2017 Author Report Share Posted September 15, 2017 @ TOMOKI: You mentioned "mica set" for the 10m90s in your earlier post. I hope you are not using regular mica insulator for this build. They don't work for voltage this high and have been known to cause short in this application. Check earlier posts and the BOM, you need Aavid 4171G and 4180G for the 10m90s and the CREE parts. Also, as Soren suggested, variac is your friend. Get one if you don't already have one. Quote Link to comment Share on other sites More sharing options...
tomoki Posted September 15, 2017 Report Share Posted September 15, 2017 55 minutes ago, mwl168 said: @ TOMOKI: You mentioned "mica set" for the 10m90s in your earlier post. I hope you are not using regular mica insulator for this build. They don't work for voltage this high and have been known to cause short in this application. Check earlier posts and the BOM, you need Aavid 4171G and 4180G for the 10m90s and the CREE parts. Also, as Soren suggested, variac is your friend. Get one if you don't already have one. Thanks for your comment and kindly remind. the mica that i use is the ceramic type one with nylon screw and nuts For the variac, I still feel a little bit confusing about the connection method. BTW, due to my job I can try my office AC power stabilizer, I think it can tune the voltage that required. 1 hour ago, congo5 said: much better photo's that 20k should never see hardly any wattage, something is bridged/blown, tracks,pins, transistors possible Q5 & Q8 direct short through all pins Thanks for your advise. I am wonder both 2 are broken. planning to replace it both. 8 hours ago, sorenb said: Original post Thanks sorenb. Just a little bit confusing the method and I would like to confirm it before test it. For the CCS, is that I should use a AC source with voltage in between 15-20VAC, then connect it between the middle leg of the 10m90s and solder pad in between R2 and R1 (also the pin 6, for the 2nd 10m90s). Quote Link to comment Share on other sites More sharing options...
sorenb Posted September 15, 2017 Report Share Posted September 15, 2017 51 minutes ago, tomoki said: ... is that I should use a AC source with voltage in between 15-20VAC DC 51 minutes ago, tomoki said: ... the middle leg of the 10m90s Yes: Gate - Drain - Source 51 minutes ago, tomoki said: ... and solder pad in between R2 and R1 (also the pin 6, for the 2nd 10m90s). Can't remember ... look at PCB and you'll figure it out; the black (negative) probe goes to the tail of the CCS The @MLA suggestion is a good advice BTW Quote Link to comment Share on other sites More sharing options...
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