Help needed for unknown SEMELAB Power Zeners "8136 8215E"

[tiefbassuebertr]

I want to know a replacement for the above mentioned zener diodes. I don't know the naming of the associated outline, but it looks similar to those under
VS-GBPC2508W | Vishay VS-GBPC2508W, Bridge Rectifier, 25A 800V, 4-Pin GBPC-W | RS Components
but with only two connectors.
The power zeners (7 pcs) are in use in a voltage regulator for creating the anode voltage of a diy tube pre-amplifier with ECL-86
Thanks for posting a URL for a data sheet.

 

[Mark Tillotson]

Photo? 8136 and 8215 look suspiciously like datecodes to me...

 

[tiefbassuebertr]

Photo? 8136 and 8215 look suspiciously like datecodes to me...

Photos probably don't provide the desired information here. The outline is not essentially different as shown in the mentioned URL


Furthermore, it is because of the baked-in thermal grease (silicon ointment) not possible to read the type numbers and modell series on the images (except the logo of manufacturer).

Nevertheless I will make images next time of those parts.

The reason for the overheating and thermal overload were unscrewed screws on the heatsink.
All zeners have zero resp. 0 Ω passage in both directions.

 

[6vheater]

8215E etc are SOVIET made 5W zeners.
I can get lots of them all different values VERY CHEAP.

 

[Vovk Z]

8215E etc are SOVIET made 5W zeners.

- I have never heard about that part numbers. Thay can't be Soviet.
Soviet ones numbered as КСххх_, or Дххх_ (ххх - three numbers), КС - silicium zener, Д - diode.
May be post-Soviet (Russian)?

 

[6vheater]

happy now???

They are written in cyrillic on the body, I should know I have loads of them - all kinds of values which I used directly in the ground return of a transformer HT CT, to give a stable bias line.
The seller has made a mistake with alphabet with the "2" instead of cyrillic D.

 

[tiefbassuebertr]

This is the usual outline for power zeners like
2 Stuck BZX98C3V9 Leistungs Z-Diode 3,9V, 13W, DO4 Gehause (AE18/7561) | eBay
and not, what I need (read post #1).
I will make photo for upload next time.

 

[tiefbassuebertr]

Photo? 8136 and 8215 look suspiciously like datecodes to me...

Here we go...

 

[tiefbassuebertr]

I count 4 pcs "8136" and 3 pcs "8149" (maybe 4x 36V and 3x 49V - at whole 291VAC for the anode voltage, but I am unsure).
When an armor plant was shut down, these Zeners from SEMELAB in military version was save.
The builder of the tube preamplifier worked here at those days.
From where I can ask for datasheets ?
The ownership of the company SEMELAB have changed in the meantime.

 

[tiefbassuebertr]

I guess, nobody can help. Even not concerning a appropriate replacement in an outline for non isolated heatsink mounting like TO-220 ISO as to find under
2SA1837 - 2SC4793 Transistor PNP npn 230V 1A TO-220ISO Toshiba (8 Stuck) | eBay.
I have found replacement (TO-3 TO-220) but only for isolated mounting on heatsink - have a look to the attached pictures.
Best solution is creating a new serial voltage regulator with high voltage - high power transistor (maybe BU/BUX series) with usual zeners.

 

[tiefbassuebertr]

I guess, nobody can help. Even not concerning a appropriate replacement in an outline for non isolated heatsink mounting like TO-220 ISO as to find under
2SA1837 - 2SC4793 Transistor PNP npn 230V 1A TO-220ISO Toshiba (8 Stuck) | eBay.
I have found replacement (TO-3 TO-220) but only for isolated mounting on heatsink - have a look to the attached pictures.
Best solution is creating a new serial voltage regulator with high voltage - high power transistor (maybe BU/BUX series) with usual zeners.

Under
A New High-Voltage Regulator
I have found the attached circuit. Instead TIP50 I want to use an ISO-outline like that one:
https://www.st.com/resource/en/datasheet/buv48a.pdf
or
BUT18AF datasheet
But what replacement are there for MJE350 in such ISO outline ?

 

[tiefbassuebertr]

check out post #11 (and #32) under
BF469, 470, 471, 472 vs. MJE340/350 are ON better?

 

[tiefbassuebertr]

Under
A New High-Voltage Regulator
I have found the attached circuit. Instead TIP50 I want to use an ISO-outline like that one:
https://www.st.com/resource/en/datasheet/buv48a.pdf
or
BUT18AF datasheet
But what replacement are there for MJE350 in such ISO outline ?

Fairchild KSA1381E - go to post #33/36 under
https://www.diyaudio.com/forums/sol...70-471-472-vs-mje340-350-a-4.html#post6207154

 

[tiefbassuebertr]

I count 4 pcs "8136" and 3 pcs "8149" (maybe 4x 36V and 3x 49V - at whole 291VAC for the anode voltage, but I am unsure).
When an armor plant was shut down, these Zeners from SEMELAB in military version was save.
The builder of the tube preamplifier worked here at those days.
From where I can ask for datasheets ?
The ownership of the company SEMELAB have changed in the meantime.

Now I have found a good replacement: 5 pcs BZY91 C56 (280V) only intended for isolated mounting on heatsink unfortunately.

 

[tiefbassuebertr]

To watch the temperature I made this as a temporary solution according the attached images (the solution in previous post was suited only for 25mA).
Without the connected pre-amp the output voltage is 285VDC and idle current through five 56V power zeners is 330mA. And with connected pre-amp (which draws 100-110mA) 230mA (outüut voltage same value).
Because the heat transfer resistance between the sub-heat sink and the main heat sink there is a temperature gradient of 10 degrees, i. e. the zeners heat up 10 degrees above the main heat sink (approximately 60-65 degrees resp. 60-65 °C, i. e. 40-45°C above ambient temperature).

Therefore I want to have heat sinks like those from post #4 under
Sub Heatsink for 6 Zener Diodes in DO5 Outline for electric isolated Mounting

Thanks for calling an ordering address.