KGSSHV Carbon Build Thread

[sorenb]

[Whitigir]

Lol, don't worry about formula, I just looked up for directions

 

Edited August 24, 2017 by Whitigir

[wink]

 

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

[gepardcv]

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.

[mypasswordis]

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. 

[johnwmclean]

http://au.mouser.com/ProductDetail/Phoenix-Contact/1790539/?qs=MfVUZiz0PxbRlZTU%2bIaPbA%3d%3d

[chinsettawong]

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

[Pars]

Or something like MG Corona Dope might help?

[wink]

Some kapton would work too....

[cloudbp]

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

[johnwmclean]

Those voltage converter boards were Spritzers, I’m pretty confident he doesn’t offer them any longer.

[tomoki]

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.

[Pars]

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.

[tomoki]

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

[mypasswordis]

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?

[tomoki]

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.

[congo5]

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

[tomoki]

 

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 

 

[sorenb]

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:

1. 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: 

1. the pin6 of lt1021 against "ground" (pin4) ....you should see 10V ...if not, the lt1021 has probably gone south
   Before raising the VARIAC further:
2. 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
3. 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

[MLA]

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...

[Helium]

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?

[congo5]

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

 

[mwl168]

@ 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.

[tomoki]

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). 

[sorenb]

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