VR Tube Question

coldcathode · 17th October 2009, 01:52 AM

If using 2 Vr tubes in series, is there a way to tap off voltage between the two? ie 2 VR150's for 300V can I pull 20mA off the junction at 150V?

I realize I would be reducing the first tubes current capability but since it can draw 40mA and I really only need about 10 more on the plus side to regulate the 300V would it be OK?

Or is the "proper" solution to put an RC off the 300V and then regulate the 150 with a 3rd VR-150?

I think I have the answer but looking for input

zigzagflux · 17th October 2009, 02:12 AM

Certainly can. Check out the datasheet

Enzo · 17th October 2009, 04:01 AM

The very first entry in my RCA book is the 0A2. it includes a couple pages of tutorial including an example of exactly what you propose.

Geek · 17th October 2009, 05:38 AM

I've read the 0D3 is the noisiest one you can use. Is this true?

Cheers!

coldcathode · 17th October 2009, 02:15 PM

Quote:

Originally Posted by Geek

I've read the 0D3 is the noisiest one you can use. Is this true?

Cheers!

I have used it on a few Power Supplys and It can be noisy but, careful attention to the design of the supply and you can quiet it right down.

a: If you can use a voltage somewhat lower than the regulated voltage and use a decent size RC filter down stream.

b: Use a small value snubber cap across the VR tube.

c: Keep it far away from the other tubes.

Gary P · 17th October 2009, 02:57 PM

Yes, you can use the junction between the VR tubes as an output. If you want to pull 20ma from the junction between the tubes you should put a resistor across the upper VR tube that sources 20ma at the voltage the upper VR tube regulates at. This will allow both VR tubes to run in the center of their current ranges even though you are pulling current out the tap.

noah300g · 6th December 2011, 08:26 PM

I have an amplifier for a Carillonic Bell system made by Schulmerich, but can't find a schematic for it. It uses 2 807 output tubes, 2 5R4 rectifiers, and two VR150 regulators. the plate transformer is starting to sizzle and smell bad unless I remove/disconnect the VR150 from its socket. With that tube removed, I can leave the 5R4's and 807's in place with no smoke or sizzle. As soon as the VR 150 is put in, bad things start to happen. Since I don't have a schematic, I'm hoping the experience of this group might help me make it work again before the transformer actually cooks all the way.
Thanks,

Wavebourn · 6th December 2011, 08:34 PM

Sure you can!

Also, pulling current from their junction you help them to ignite initially, lowering down starting voltage such a way.

17th October 2009, 01:52 AM	#1
coldcathode diyAudio Member Join Date: Jan 2009	VR Tube Question If using 2 Vr tubes in series, is there a way to tap off voltage between the two? ie 2 VR150's for 300V can I pull 20mA off the junction at 150V? I realize I would be reducing the first tubes current capability but since it can draw 40mA and I really only need about 10 more on the plus side to regulate the 300V would it be OK? Or is the "proper" solution to put an RC off the 300V and then regulate the 150 with a 3rd VR-150? I think I have the answer but looking for input

6th December 2011, 08:26 PM	#7
noah300g diyAudio Member Join Date: Dec 2011	need help with Schulmerich 6-142 amplifier I have an amplifier for a Carillonic Bell system made by Schulmerich, but can't find a schematic for it. It uses 2 807 output tubes, 2 5R4 rectifiers, and two VR150 regulators. the plate transformer is starting to sizzle and smell bad unless I remove/disconnect the VR150 from its socket. With that tube removed, I can leave the 5R4's and 807's in place with no smoke or sizzle. As soon as the VR 150 is put in, bad things start to happen. Since I don't have a schematic, I'm hoping the experience of this group might help me make it work again before the transformer actually cooks all the way. Thanks,

6th December 2011, 08:34 PM	#8
Wavebourn diyAudio Member Join Date: Sep 2006 Location: Pleasant Hill, CA	Sure you can! Also, pulling current from their junction you help them to ignite initially, lowering down starting voltage such a way. __________________ The devil is not so terrible as his mathematical model! Wavebourn: We Create Creativity!

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17th October 2009, 04:01 AM	#3
Enzo diyAudio Member Join Date: Sep 2004 Location: Lansing, Michigan	The very first entry in my RCA book is the 0A2. it includes a couple pages of tutorial including an example of exactly what you propose.

17th October 2009, 05:38 AM	#4
Geek diyAudio Member Join Date: Sep 2004	I've read the 0D3 is the noisiest one you can use. Is this true? Cheers!

17th October 2009, 02:57 PM	#6
Gary P diyAudio Member Join Date: Apr 2002 Location: Portland OR	Yes, you can use the junction between the VR tubes as an output. If you want to pull 20ma from the junction between the tubes you should put a resistor across the upper VR tube that sources 20ma at the voltage the upper VR tube regulates at. This will allow both VR tubes to run in the center of their current ranges even though you are pulling current out the tap.

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