Last-PAS Reg B+ Board GB Inquiry - Page 3

jackinnj · 31st October 2005, 01:33 AM

the boards will be in sometime around November 22nd.

leadbelly · 8th November 2005, 05:25 PM

Quote:

Originally posted by jackinnj
the boards will be in sometime around November 22nd.

Am I still in? Payment now or then?

SY · 8th November 2005, 05:28 PM

Ditto!

jackinnj · 8th November 2005, 07:48 PM

I will post a note when they get in. Due date is still Nov 22.

jackinnj · 8th December 2005, 08:57 PM

Well, the boards are in, but I don't like the results -- all of the work is done by the 1K resistor -- and if the B+ on the input rises to, say, 400V the current limiter formed by the LM317/120R resistor seems to fail at its job and we start to get white smoke. Kind of like the old joke -- looks good feels bad (1). Even without the filter caps, and extensive zener filtering the output looks very clean indeed, but it just doesn't regulate. I also had a design error which was my fault -- this was easy enough to correct. A couple folks sent $ to my PayPal account which I have returned. I don't want to disappoint.

(1) This joke is not to be repeated in "pleasant company" and I repeat it not here for fear of the sin bin.

Andypairo · 10th December 2005, 08:00 AM

Hello Jack,
the mistake was in the layout or in the circuit?
Since I've bought (besides the PCBs that were refunded for) also the BJTs to build this regulator, I'm still willing to use it, even if only on veroboard.

Please advice.

Andrea

jackinnj · 10th December 2005, 01:10 PM

I rewired with BU208A instead of the MJE3439 -- once the devices get cooking (I see about 25 ma out of the power supply -- 12 ma for the zeners and 13 ma for the load resistor) the voltage creeps up from 284 to 308. I am using 5 watt zeners so they aren't getting fried.

There was a small error on the board -- not difficult to fix but it p*sses me off that I made a stupid mistake -- too much hubris. I wanted to move the zener string to a location where it would get some ventilation -- certainly not a problem if you are using a TO-3 pass transistor.

I have your address and will send a pair of boards -- let me know how you do.

Andypairo · 17th December 2005, 09:32 PM

Quote:

Originally posted by jackinnj
I rewired with BU208A instead of the MJE3439 -- once the devices get cooking (I see about 25 ma out of the power supply -- 12 ma for the zeners and 13 ma for the load resistor) the voltage creeps up from 284 to 308. I am using 5 watt zeners so they aren't getting fried.

There was a small error on the board -- not difficult to fix but it p*sses me off that I made a stupid mistake -- too much hubris. I wanted to move the zener string to a location where it would get some ventilation -- certainly not a problem if you are using a TO-3 pass transistor.

I have your address and will send a pair of boards -- let me know how you do.

Very kind.

Will let you know how they work.

Cheers

Andrea

jackinnj · 18th December 2005, 03:56 PM

i had used some EBC transistors, the MJE3439 should fit OK (as Rich points out - MJE3439 is ECB). Will change the picture as soon as I regain access to Adobe Photoshop -- but I fried my main computer last week.

jackinnj · 20th December 2005, 11:30 PM

Here's a graph of V(in) X-Axis) vs V(out) -- and Zener Current (Left Y-axis) -- etc., etc.:

8th November 2005, 05:28 PM	#23
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX Blog Entries: 1	Ditto! __________________ “Listening to records is like ****ing a picture of Brigitte Bardot.” - Sergiu Celibidache

10th December 2005, 08:00 AM	#26
Andypairo diyAudio Member Join Date: Sep 2002 Location: near Milano , Italy	Yes I'm one of those.... Hello Jack, the mistake was in the layout or in the circuit? Since I've bought (besides the PCBs that were refunded for) also the BJTs to build this regulator, I'm still willing to use it, even if only on veroboard. Please advice. Andrea __________________ I don't believe in audiophile components - except when I can get them at frugal-phile(tm) prices

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31st October 2005, 01:33 AM	#21
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	the boards will be in sometime around November 22nd.

8th November 2005, 07:48 PM	#24
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	I will post a note when they get in. Due date is still Nov 22.

8th December 2005, 08:57 PM	#25
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	Well, the boards are in, but I don't like the results -- all of the work is done by the 1K resistor -- and if the B+ on the input rises to, say, 400V the current limiter formed by the LM317/120R resistor seems to fail at its job and we start to get white smoke. Kind of like the old joke -- looks good feels bad (1). Even without the filter caps, and extensive zener filtering the output looks very clean indeed, but it just doesn't regulate. I also had a design error which was my fault -- this was easy enough to correct. A couple folks sent $ to my PayPal account which I have returned. I don't want to disappoint. (1) This joke is not to be repeated in "pleasant company" and I repeat it not here for fear of the sin bin.

10th December 2005, 01:10 PM	#27
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	I rewired with BU208A instead of the MJE3439 -- once the devices get cooking (I see about 25 ma out of the power supply -- 12 ma for the zeners and 13 ma for the load resistor) the voltage creeps up from 284 to 308. I am using 5 watt zeners so they aren't getting fried. There was a small error on the board -- not difficult to fix but it p*sses me off that I made a stupid mistake -- too much hubris. I wanted to move the zener string to a location where it would get some ventilation -- certainly not a problem if you are using a TO-3 pass transistor. I have your address and will send a pair of boards -- let me know how you do.

18th December 2005, 03:56 PM	#29
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	i had used some EBC transistors, the MJE3439 should fit OK (as Rich points out - MJE3439 is ECB). Will change the picture as soon as I regain access to Adobe Photoshop -- but I fried my main computer last week.

20th December 2005, 11:30 PM	#30
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	Here's a graph of V(in) X-Axis) vs V(out) -- and Zener Current (Left Y-axis) -- etc., etc.:

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