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echoplex

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Hi Volker,

Will you ever consider a „Light“ Version of your 500 Series floor-Box PSU for smaller racks and even single two slot frames?
Only 1 channel, less power, smaller toroid, smaller box, smaller price :) ?
 

TillM

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echoplex said:
Hi Volker,

Will you ever consider a „Light“ Version of your 500 Series floor-Box PSU for smaller racks and even single two slot frames?
Only 1 channel, less power, smaller toroid, smaller box, smaller price :) ?

Volker has developed it years ago.

https://groupdiy.com/index.php?topic=59672.0

Just drop him a mail.
 

Majestic12

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TillM said:
Volker has developed it years ago.

https://groupdiy.com/index.php?topic=59672.0

Just drop him a mail.


I guess Volker has some of the PCBs in stock. I have built one of those two slot frames for some 24V modules I had lying around, but it came out very expensive for "only" two 511 series slots.
 

TillM

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I ordered my PSU at Segor.
They have really small 22VAC toroidal transformer who fits perfectly in the 1U case.
Yes it’s an expensive project for just two slots, but I like the option of 24v rails without buying the whole 11 slot rack.
 

[silent:arts]

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D-LA2A PSU transformers, RK7-Adapter PCBs for mounting Haufe RK and Pikatron RÜP transformers, Carstens Discrete OpAmp Test Jig and GDIY 51X Card Edge Adapter PCBs for your prototypes are back in stock.

Coronavirus Pandemic Annotations:
1) restrictions to international mail and parcel services
2) only 16% VAT to EU buyers until the end of the year (if applicable)
 

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Spencerleehorton

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I'm having weird problems with the pn48v psu, double checked all parts in correct orientation,  checked solder joints, using 24v toroidal no centre tap, but only getting 27v after first diode bridge and only 38v after 2nd diode bridge?
This is to power 4 x neve 1290 with 48v.

Have replaced 317 on 48v and still the same?

When I wind up 337 to 24v it takes down pos voltage!!!!???

Could do with some help please as I have two of these
 

Spencerleehorton

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I connected the ac connections to both ac connections on toroidal and gnd is connected to iec, through 10R resistor.

Your probably going to say a 2 lead toroidal wont work as its 0v and 24v ac and I need to use a 3 connection config with centre tap and make sure it's set to x3 to get 48v!?
 

Spencerleehorton

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just rigged up a 2 x 15v centre tapped toroidal that i had and its sorted the 48v with the x3 the positive 317 is now gone, so will replace, i probably fried it with the first config!! hopefully out of trouble now!!
 

Spencerleehorton

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Dont like putting negative posts but im gonna have to moan sorry!!, the PN48PSU which i bought two of i've had no info on what voltage caps are needed, none in the document that i downloaded, is there another bit of info im missing?

Also, no info on what transformer to use with it? also is there info that i'm missing somewhere?

I have now changed all 317's and 337s and im getting voltages but the PSU doesnt deliver +24v or -24v with 48v?
Im using a 2 x 15v toroidal and it only gets +21v -21v and 48v?

I thought it was meant to deliver +37v -37v and +65v?

regards

Spence.
 

[silent:arts]

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Spence, I'm sorry if you are not satisfied with your PCBs and the schematic you can download here.

Spencerleehorton said:
I have now changed all 317's and 337s and im getting voltages but the PSU doesnt deliver +24v or -24v with 48v?
Im using a 2 x 15v toroidal and it only gets +21v -21v and 48v?
For +/-24V you need at least a 2 x 20V transformer (or 1 x 40V with center tap).

Hope this helps
Volker

PS:
Spencerleehorton said:
This is to power 4 x neve 1290 with 48v
Why did you choose the PN48PSU for this?
 

Spencerleehorton

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ah ok, well i'll order a 2x20vac, i thought maybe it was that but wasnt sure.

Would a 2 x 18v 20va be ok?

I ordered that as thats what i thought you did which covered what i needed?

I dont mean to be negative just thought it would be a good idea to include this other information.

thanks again dude.

regards

Spence.
 

jensenmann

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When you´re using a bridge rectifier then you get in theory app. Vdc = Vtranny  x 1,6  at the smoothing caps (in front of the regulators). In realworld use it´s safer to calculate with 1,4 instead of 1,6 to equal out possible weaknesses of the transformer. The regulators should see an input voltage of 3v higher than the required output voltage.

So if you calculate that backwards you´d want to have 27V at the regulator input for 24V output. Vtranny = Vdc/1,4 = 27V/1,4 = 19,3V. Volkers recommendation of 20V is spot on!
 

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