KRAFTWERK Power Supply BUILD THREAD

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Massimoaxl
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Massimoaxl » Tue May 24, 2016 4:20 am

Hi Joe, your' pcb arrived 2weeks ago, i'm triyng to build it in order to use it with some 500 modules, so i need only the +/-16v rails and the 48v.
About the jumper in front of the bridge rect, how should be connected? there are 3 pin I'm a bit confused.
Can't find 3300uF cap to fit the board can I use 2200uF?
Thank you!
Alex

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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Joe Malone » Tue May 24, 2016 8:13 am

Massimoaxl wrote:Hi Joe, your' pcb arrived 2weeks ago, i'm triyng to build it in order to use it with some 500 modules, so i need only the +/-16v rails and the 48v.
About the jumper in front of the bridge rect, how should be connected? there are 3 pin I'm a bit confused.

If you are using 2 x 18vac transformer which is the best for +/-16v then set a link C to T for tripler. If you are 2 x 22v to 25vac then link C to D for doubler. This sets the pump charge for the 48v rail.

Can't find 3300uF cap to fit the board can I use 2200uF?
Thank you!
Alex


Yes it will work but have less cap smoothing for the unregulated dc rails, so makes it harder for the regulators to keep regulation under full load. But if you are only running one 10 way 500 rack it will be fine.
Joe :-)
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Massimoaxl
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Massimoaxl » Fri May 27, 2016 6:34 am

It's working :D!

Image

Image

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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Joe Malone » Fri May 27, 2016 7:53 am

Massimoaxl wrote:It's working :D!


OK good to hear it is going but STOP and turn it OFF and please read below.

None of the regulators have there insulating silicon tubes over them to stop them shorting to the metal case? So if it is working I presume none of them are actually touching the case so have no heatsinking. If they all touch the metal case it will blow the power supply.

The four large bolts between the 5 regs are needed to squeeze the regulators in there silicon insulation tubes to the case for heatsinking. Also that case will only give enough heatsinking for maybe 8 to 10 x 500/51X modules. When running that many modules the case will be so hot it could burn you.

Also not legal to have a power transformer out in the open where it can be touched.
Joe :-)

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Massimoaxl
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Massimoaxl » Thu Jun 09, 2016 6:06 pm

Hi joe!
Nothing is touching the case, for securiy i have added some rubber under it!
What do you think of adding a little 24v fan? (like those used for Pc grafic board?)
I'm using 2200uF caps (can't find so small 3300uF) so I'm not gonna to use it for more than 10 module I guess!

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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Joe Malone » Fri Jun 10, 2016 8:27 am

Massimoaxl wrote:Hi joe!
Nothing is touching the case, for securiy i have added some rubber under it!
What do you think of adding a little 24v fan? (like those used for Pc grafic board?)
I'm using 2200uF caps (can't find so small 3300uF) so I'm not gonna to use it for more than 10 module I guess!


The regulators must be bolted hard to the metal case or heatsink with silicon insulator kits so they do not short to the case and so they have good heatsinking. Then a fan would be a good idea in that small metal box like that. But if the regulator metal tabs are not touching anything heatsink wise you will not be able to run any modules as they will overheat at about 200mA current draw.
Joe :-)

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tonefreq
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby tonefreq » Sun Aug 14, 2016 1:10 pm

image.jpeg
Hey, Joe,
Am I smoking crack? (Wait..don't answer that)
Got everything hooked up, RS Torroid Transformer, 671-9173, BLU-VIO to Neutral, BRN-GRN to fused live (1A fuse) Secondaries, RED, YEL to AC, BLK, ORN to 0V

Flipped power, blew fuse. Disconnected the secondaries from the board, And STILL blew a fuse... Checked everything for shorts on the 115V end, and it seemed fine, flipped power and measured 28V on the secondaries. SO, I checked the Kraftwerk board, everything seemed OK. No fried parts, everything installed correctly, no shorts. So I hooked it up again.
Fuse blown. Disconnected the secondaries again, and replaced the fuse. Flipped the power and blew another fuse. I'm out of fuses, and patience. And thoughts, or ideas of what could be going on? I've done something like 20 of the AC/DC kits without problems, but this one is stumping me.

Many thanks!
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tonefreq
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby tonefreq » Sun Aug 14, 2016 1:11 pm

Transformer
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Joe Malone
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Joe Malone » Mon Aug 15, 2016 9:36 am

tonefreq wrote:
image.jpeg
Hey, Joe,
Am I smoking crack? (Wait..don't answer that)
Got everything hooked up, RS Torroid Transformer, 671-9173, BLU-VIO to Neutral, BRN-GRN to fused live (1A fuse) Secondaries, RED, YEL to AC, BLK, ORN to 0V

Flipped power, blew fuse. Disconnected the secondaries from the board, And STILL blew a fuse... Checked everything for shorts on the 115V end, and it seemed fine, flipped power and measured 28V on the secondaries. SO, I checked the Kraftwerk board, everything seemed OK. No fried parts, everything installed correctly, no shorts. So I hooked it up again.
Fuse blown. Disconnected the secondaries again, and replaced the fuse. Flipped the power and blew another fuse. I'm out of fuses, and patience. And thoughts, or ideas of what could be going on? I've done something like 20 of the AC/DC kits without problems, but this one is stumping me.

Many thanks!

Remember toroidal transformers even with nothing connected have huge startup surge so you will usually have to use a slow blow fuse to survive the startup surge.

So on 115vac the 225VA transformer will draw 2A at full load. So you will need a 2AT slow blow fuse.

On 230vac the 225VA transformer will need 1A at full load. So you would need a 1AT slow blow.

Some toroidal transformer surges are so large that they determine the fuse size so you may find you need a 3AT etc

Also you have the secondary wiring wrong. The two winding should be working out of phase to each other so you get 100 or 120Hz cap voltage refresh rate. The way you have it the refresh rate will be 50 or 60Hz. So Secondaries should be, RED, OR to AC, BLK, YEL to 0V for best operation.
Joe :-)

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tonefreq
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby tonefreq » Mon Aug 15, 2016 10:46 am

Awesome. Thank you. I figured that it was the transformer pulling current, I had no idea it would be that much though. Good to know! And I'll let the secondaries down if it's the end of me. Thanks for the help
SG

tonefreq
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby tonefreq » Tue Aug 16, 2016 9:21 am

Looks like the 2A slow Blow fuse did the trick. I was getting close to proper voltages on all the rails..... Then I blew C1. :shock: Getting 28V from the transformer, which should be fine,.. Will have to check to see if there's a short somewhere. Hope something didn't short out against the case..... Back to the woodshed!

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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Joe Malone » Tue Aug 16, 2016 9:48 am

tonefreq wrote:Looks like the 2A slow Blow fuse did the trick. I was getting close to proper voltages on all the rails..... Then I blew C1. :shock: Getting 28V from the transformer, which should be fine,.. Will have to check to see if there's a short somewhere. Hope something didn't short out against the case..... Back to the woodshed!


Check you are set to doubler and all caps & diodes are fitted in the correct polarity.

28vac from the transformer is fine.
Joe :-)

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XAXAU
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Re: KRAFTWERK Power Supply BUILD THREAD

Postby XAXAU » Wed Dec 07, 2016 5:21 am

Hi Joe!

Built my Kraftwerk today but it seems the 10R carbon resistor was missing. I have a 10R metal that was left over from my VU2 buffer build, can I use that one instead? If not, no biggie, I´ll be ordering parts from Mouser soon anyway. What´s the wattage rating on the carbon resistor?

Cheers!

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Re: KRAFTWERK Power Supply BUILD THREAD

Postby Joe Malone » Wed Dec 07, 2016 7:48 am

XAXAU wrote:Hi Joe!

Built my Kraftwerk today but it seems the 10R carbon resistor was missing. I have a 10R metal that was left over from my VU2 buffer build, can I use that one instead? If not, no biggie, I´ll be ordering parts from Mouser soon anyway. What´s the wattage rating on the carbon resistor?

Cheers!


Sorry to hear about the missing part. I will have all the kraftwerk kits checked today. Thanks for letting me know.

But yes you can use the 10R metal film resistor. Carbon resistor is 1/4W, blue metal film 1/4W, Green metal film 0.6W
Joe :-)

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