i'm on a roll... the kgsshv

[eggil]

Kerry, I hadn't seen measurements on the kgsshv before. Thanks.

Shipsupt, we demand pictures!

[insanity]

Hey guys, I have a question.

I have just been populating the KGSSHV boards from lil knight's latest board run. I noticed that on the psu board there are no more 20k resistors, although the schematic shows two. Can someone elaborate on this?

 

Furthermore, since this is Rev 0.61 of the amp board, if you use the ixys part, you need 250ohm resistors instead of 180. I ordered the wrong ones... The BOM has been updated for this, but I missed it...

Could someone tell me what the specs of these resistors must be? I probably have noname 10% 1/4W. But if I need 50ppm and 1/2W I need the order some.

 

In the schematic of the psu board, the two 3900pf 1000V caps are not shown (unfortunately didn't order them...)   I cannot find any suitable in stock 3900pf caps at mouser. Can I use 3300pf instead?

 

I'll continue stuffing the boards, hoping I didn't miss anything else 

 

Thank you.

[RiStaR]

Hi Insanity,

 

I'm pretty sure I'm using these 3900pf capacitors in my 0.5 version. It's 630V and I haven't had an issue with them since I got it up running for more than half a year with daily listening

 

http://sg.mouser.com/Search/ProductDetail.aspx?R=FK20C0G2J392Jvirtualkey52130000virtualkey810-FK20C0G2J392J (Please note: It's on an SG site)

[eggil]

Hey guys, I have a question.

I have just been populating the KGSSHV boards from lil knight's latest board run. I noticed that on the psu board there are no more 20k resistors, although the schematic shows two. Can someone elaborate on this?

 

WOT! In mine they are to the left of the 440's and on front of the 50k's

[livewire]

Yup, must be a n00bish thang.

[insanity]

WOT! In mine they are to the left of the 440's and on front of the 50k's

Lol I missed that. I had them populated. I had ordered a total of 8 and therefore expected 2 to be leftover. I had 4 left. Looks like they shipped 10! Sorry for that one...

[spritzer]

Yeah,,, missing 20K units would make no sense as it sets the output voltage. 

 

3900pf should be 1000V or more. 

[GeorgeP]

Weren't the 3900pf caps on the psu optional? Or has that changed for the mini version?

[Kerry]

I didn't use the 3900pF cap in my version.  A lower capacitance would certainly work.

 

I didn't do a comparison of the difference under load.  Under no load and with either version I was unable to measure the noise level since it is so small.  In LTSpice it was slightly lower noise without that cap.

 

Kevin  probably had a reason for including it but I'm not clear on it though I'm guess it would be to prohibit oscillation.

[spritzer]

They are optional so feel free to leave them out.  The smaller layout is completely the same as the bigger boards.... just smaller. 

[insanity]

I have another two questions concerning the leds on the amp boards. 

 

1. In the BOM I used (not the most recent version) the specified led is Vf 1.7V 2mA. After my calculations this is what fits with the 10k resistor at 15V. 

The ones I ordered are Vf2.1V 20mA. I guess that these won't light up with this configuration, right?

I would therefore exchange the leds. 

Unfortunately with my limited knowledge of electronics, I am unsure, if the leds are mandatory for the circuit to function. Are they?

 

2. Is it correct, that there are two unpopulated LED locations on the board, if the IXYS Parts are used? (same as with the resistors/different values)

[GeorgeP]

No offence, but these are not very confidence inspiring questions. It also sounds like you may not have read through the thread fully, and this is a very dangerous build given the high voltage.

[insanity]

No offence taken. I expected a similar answer, but I am just asking these questions to be absolutely sure. I have successfully built a working B22 with LCDuino without blowing anything (see http://www.amb.org/forum/post-pics-of-your-builds-t44-600.html#p18554). I know its certainly not HV, but just to make clear that I may not be as unexperienced as these questions may suggest. 

I don't know if you agree, but IMHO to build these projects are well buildable even if one doesn't completely understand the working nature of the schematics. 

In case of this build, I think the problem is that I do not have the latest (complete) schematic. The one on lil knights site, has some parts missing from the most recent updates. But with some common sense and intelligence they are well buildable. 

Just to calm you down a bit: Although I am no electronics engineer, I happen to be MD (hope this implies some intelligence lol). 

 

Furthermore I have read most of this thread. The problem here again is the changing nature of this project and it's unofficial BOMs. 

 

Just to state this once more: I would like to express my thanks to the creators and supporters of these projects (i.e. KG, spritzer, lil knight and many more).

No offence, but these are not very confidence inspiring questions. It also sounds like you may not have read through the thread fully, and this is a very dangerous build given the high voltage.

[livewire]

#1 - Your leds are crap, buy the right ones if you expect anything to function.

 

#2 - Correct.

 

#3 - Insane doc, make sure that you have a defibrillator on hand while working on the amp / psu while under power. You may need it.

[insanity]

#1 - Your leds are crap, buy the right ones if you expect anything to function.

 

#2 - Correct.

 

#3 - Insane doc, make sure that you have a defibrillator on hand while working on the amp / psu while under power. You may need it.

1+2: Thank you very much.

3: Am I really that insane?

[livewire]

You're welcome.

 

I don't know (you). Your board name implies it.

 

I hope for your sake that you have basic knowledge working with high voltage.

Your questions do not inspire confidence in those of us who have built these things.

Good luck!

[insanity]

I will surely take cover and be quite far away when first powering that thing up...

 

I totally forgot about that forum name 

 

 

You're welcome.

 

I don't know (you). Your board name implies it.

 

I hope for your sake that you have basic knowledge working with high voltage.

Your questions do not inspire confidence in those of us who have built these things.

Good luck!

[jwzhan]

hmm... I thought the amp board has 4 leds for 1968 and 3 leds for IXYS... did I miss something here？

[insanity]

On the latest board from lil knight 2 of the 4 leds are marked "A" implying they need to be left out for the IXYS parts. 

But since I am missing the schematic for these boards, I asked this question. When looking at the boards, there are some new traces and additional resistors not seen in the schematic. 

 

What board version do you have?

[jwzhan]

Which board do you have? This?

Schematic with the old parts is here. You should use those older and probably better parts anyway.

There are at least 2 big revisions since I built mine, but I was under the impression that they are only small tweaks like adding the servo... Maybe I'm just talking out of my behind....

[insanity]

I have a newer version than you show. Thats the schematic i have. 

 

If you permit another question: Is 1/4W enough for the 787k resistor in the Voltage multiplier string? I ordered 1/4W version of this: http://www.vishay.com/docs/30260/hvr25.pdf As stated in the latest BOM. 

 

I also have the 1/2W 787k of this: http://www.mouser.com/ds/2/351/XC-600046-204245.pdf But its only rated 350V working voltage. 

 

I am not certain about the voltage/current this resistor sees. When I looked at pictures of finished kgsshv builds, I saw many different resistors in use some look like 1/4W some like 1/2W, but I could not clearly identify all. I am building the 450V version.

 

I could also use two 1/2W resistors in series (i.e. 300k and 487k). I have those.

 

What is the best to do?

[insanity]

I just thought I could add some pictures.

 

 

Just before someone screams: I use metal screws on the IXYS Parts. I checked with Birgir and with these isolating washers and ceramic pads this works for him. 

 

The 1.2k resistors of the CCS are rated 1/2W, but are 100ppm. Didn't have anything else.

 

On the small heatsinks of the PSU, I had to improvise because holes were made for some american size screw I did not have. Isolation is the same as on the amp boards. 

 

The rectifiers are soldered a bit oblique, because I thought it couldn't hurt to get some more distance between these non isolated tabs...

 

I have not yet received the toroid, so no firing up atm.

[insanity]

 

This is the new section on my boards, which I was talking about in my earlier posts.

[spritzer]

Not sure why that LED in the corner is labeled A... shouldn't be. 

 

Uninsulated diodes on the HV are not recommended.  I'd remove them and fit the correct ones, the ones printed on the PCB. 

 

Ohh and one more thing, never... ever try to change the feedback with the amp running. 

[insanity]

Not sure why that LED in the corner is labeled A... shouldn't be. 

 

Uninsulated diodes on the HV are not recommended.  I'd remove them and fit the correct ones, the ones printed on the PCB. 

 

Ohh and one more thing, never... ever try to change the feedback with the amp running. 

So LED in the corner needs to be in but the adjacent 2x 175k left out? correct?