Building an Unregulated Linear Power Supply

[oneguy]

That was just with the cases being side-by-side. The intent when all was said and done was to take the output from the last cap. 
 

I chose to star ground the negatives which is similar to what Rico25 did. This was an attempt to lower impedance.

[oneguy]

Double star would look something like this:

[oneguy]

I used a 1KΩ2W metal film resistor until I found that just letting the Taiko in the server bleed it down works really well too IIRC from my test I was under a volt in less than 10 min. 

[oneguy]

1 minute ago, Exocer said:

This works if the lps is connected. If it isn’t, you should discharge before connecting it.

100% truth unless you like arcing and sparking. 

[oneguy]

Just now, Gavin1977 said:

Oh yes, I’ve been there before… can you tell?!

So have I!🤣

[oneguy]

I may have missed it. Any specs on the rectifier yet?

[oneguy]

On the subject of the soon to be released Taiko/Mundorf 220,000uF:

-Doesn’t swapping multiple smaller capacitance capacitors in parallel for a single large capacitance capacitor mean the ULPS will have a worse ESR?

-220,000uF is a significant increase in capacitance compared to the original 5A/V3 design (116,000uF or 141,00uF depending on which source you look at). For reference the 10A/V3 called for 220,000uF and 12A/V3 called for 330,000uF

[oneguy]

4 hours ago, JJSim said:

The single 220,000µF HC cap will have lower ESR than multiple smaller caps in parallel. The 47,000µF HC cap has an ESR of 3 mOhm, so expect the 220,000µF to be lower still. The Taiko/Mundorf cap will also take up less room overall than five caps, and eliminating the wiring/connectors tying the caps together will lower resistance in the power supply.

 

Keep in mind that Mundorf's ratings are a little misleading. For example, they rate ESR at 100 Hz while pretty much every other manufacturer rates it at 120 Hz, so Mundorf's specs do look better on paper.

 

https://www.hificollective.co.uk/sites/default/files/mundorf-mlytic-hc-datasheet.pdf

Are parallel ESRs calculated differently than parallel resistances from resistors? Using the parallel resistor calculations I get an ESR of 0.88mOhms for three 47,000uF capacitors and one 22,000uF capacitor in parallel. 

[oneguy]

Excuse my error, for a direct comparison I should have done four 47,000uF capacitor and one 22,000uF capacitor which is a total capacitance of 210,000uF. Using the parallel resistor calculations I get a combined ESR of 0.68mOhms. 

 

[oneguy]

3 hours ago, bit01 said:

@oneguystrictly speaking it is the impedance that is in parallel as you have series resistance, capacitance and some inductance, but you are right that the ESR should be lower than that of the single cap. One has to compare to the physically larger cap spec. (in this case the Taiko/Mundorf?) as they tend to have lower ESR values to begin with.

Here is a general view on advantages of II'ng in power supplies

 

Crossing my fingers that we’ll have something concrete soon and the Mundorf can drop the impedance greater than 77% over the 47,000uF/40V HC capacitor with their 220,000uF capacitor. 

 

2 hours ago, MarcelNL said:

a while ago I was considering paralleling many smaller Electrolytics and did some research, to find out that larger caps should be better...I'll try find the article, it was written with high end audio as background, not just any EE babble.

Recall it's the additional resistance of all the connections.

I’d be very interested to read that article and see how they quantified the connections.
 

I’m hoping that the copper screws and washers I used can lower whatever loses are at the connections. When I’m happy with the final performance of the ULPS I plan on cleaning all of the copper with Brasso and a toothbrush then applying Stabilant 22 to the connections.  

[oneguy]

Game on: the taiko parts are now available in your email. 

 

[oneguy]

For those curious about the amount of noise put into the line by well made audio components, take this as a sample point:

 

Everything unplugged from wall in bedroom (measured at wall):

 

All network gear plugged in (measured at power strip). UniFi USG, UniFi Switch 8, modem, Stealth 8 speakers:

Everything above plugged in but all audio gear plugged into isolation transformer turned off (measured at isolation transformer power strip):

 

All audio gear turned on (measured at isolation transformer power strip). Yggy LiM, 2x Hypsos, Mercury Streamer, ULPS V3:

 

Sam condition as above except with a 200VA load on the ULPS (fluctuating between 9 and 10mV):

 

I plan to post some measurements later related to the ULPS from my EMF meter in case the group is curious. Just need to figure out all the sceneries I want to test. Will also test after the 220,000uF cap and after the Toroidy transformer. 

 

…Don’t sleep on your server 

[oneguy]

I am going to avoid shielding testing. Just posting data for the curious. I already have enough audio based neuroticisms. 

[oneguy]

After several iterations I think I’m solid on my next ULPS plans. 

This is inside the standard modushop case that most people buy. The thicker lines are silver plated copper bus bar. Only about 11.25” required. The thinner lines are 2x2mm Angelique. About 6” total required.

 

I think this is just about as short of runs as you can manage thus lowering resistance. Also only 4 ring terminal connectors are need (besides for the bypass caps) lowering the resistance of having a multitude of connections. 
 

Bonus:

I found out that the DCR listed on the Mouser website for the 195J10  is incorrect. Mouser references 0.070ohms. After looking at the spec sheets there were transcription errors with the C30, C50, E100, G30, G75, J10, J30, M20, M30, P20, R10, T10, D25, and K6 here (https://www.mouser.com/datasheet/2/177/195_196-980958.pdf). I notified Hammond and they fixed the table (corrected version: https://www.hammfg.com/electronics/transformers/choke/195-196). 
 

Long story short, the 195J10 has a slightly higher DCR than the 195J12 (0.087ohms vs 0.072ohms) and not the other way around as previously thought. Because of that I ordered 195J12 for the other ULPS I plan on building. For reference, the 159ZJ is most commonly used has a DCR of 0.160ohms. 

 

Same basic layout just slightly different choke dimensions for a J12 based ULPS. 
 

 

I plan on having the J12 version built next month and if anyone wants a J10 version let me know. I have everything on order except the transformer and whatever output connectors you may want. 

[oneguy]

If you are referring to the Taiko rectifier board, the C2 spot is for the 22,000uF capacitor. C1 is for the bypass capacitor. 
 

The 80v/40v caps cap be used in the same system. It doesn’t matter. Those ratings aren’t what they output. They are the maximum rated voltage potential that they can handle before breaking down. 

[oneguy]

@ExocerWith only 3 nodes (two caps and a rectifier output) plus the power output is star grounding even worth it? To me is seems that adding an extra ring terminal interfaces of a star point not on a capacitor terminal would kind of negate any benefits. 
 

What I view as optimal is taping negative for the power output off of the 22,000 uF which effectively makes the star to node length zero there and the star to rectifier and star to 220,000 cap is just the length of wire their respective wires. 

[oneguy]

This is what I was trying to convey:

 

Both are effectively star grounding but the lower options reduces the amount of rings required by 2. 

[oneguy]

Dry fit looks good gonna have to jack up the chokes and caps considerably to get them level with the 220,000. 

[oneguy]

Anyone have a source where I can order Panzerholz? I am looking at either that or Permali to go underneath the chokes (36mm thick for the J10) and 22,000 HC cap (29mm thick).

[oneguy]

29 minutes ago, basillus said:

I got my panzerholz from Markus Mallits, Austria at ebay here:

https://www.ebay.com/itm/OBO-PAG-Festholz-Panzerholz/133742861561

 

I bought some rest parts, but I also got Markus to cnc special sizes and thicknesses that I needed, for example a 4 cm x 48.3 cm x 50 cm for a base for my hopefully upcoming Taiko Diy cabinet, but like so many other things his panzerholz and shipping have gone up since I ordered my parts and it is in Europe... I also have his email address.

Thanks for the lead. I’ll PM you for further info.