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Mark Johnson's VRDN Bipolar PS for Line Level +/-11 - 20V Circuits

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#62
Bill:

I've only ordered pcbs twice and both times it was from JLCPCB.com. Mark Johnson recommended them and each time I compared their pricing against 3 or 4 other fab houses; JLCPCB was the least expensive. Ordering from them (and most of the competitors I looked at) is really easy so long as you have a zip file containing all of the necessary Gerber files.

I have no allegiance here - if I were to host another group buy I'd do a quick market survey (including JLCPCB) and see who offered the best deal.

Regards,
Scott
 
#67
Hello VRDN owners, please have a look at the VRDN thread, specifically post #198.

The Rev.A VRDN managed to oscillate (!) if you built it with TI chips. It worked fine and did not oscillate if you built it with ON Semiconductor chips. I built my prototypes and first three VRDN boards with ON Semiconductor chips, and was blissfully unaware of the oscillation until a member notified me.

Post #198 shows new component values (4 resistors, 2 capacitors) which allow the existing VRDN PCBoard to work well, and not oscillate, with chips from either TI or ON Semiconductor. I'm calling it Rev.A2 to indicate that the Rev.A PCBs which you own right now, are okay. You just stuff and solder different valued parts into the existing component footprints. Head over there and take a look.

VRDN: bipolar regulator PCB for line level ckts: ±11V to ±20V @ 1.5A with "De-Noiser"
 
#70
PCBs received. Thanks. The postal clerk at my local post office whom I have known since she was a little girl, when I asked if she was alright replied, "No I am not" then became almost speechless which at this point I could feel her stress. However, she did remember to thank me and wish me a happy holidays. The postal employees are in the trench and on the frontline for sure.
 
#71
Harry:

I couldn't agree more. Our postman has been a lifeline this year. In brief conversations he has noted the flood of work, limited support and the incremental pressure commonly felt in the USPS. When he delivered our mail yesterday, I thanked him for his service and gave him a bottle of a particularly nice Zinfandel. I hope his holidays are warm and relaxing -- he deserves a nice break.

Regards,
Scott
 
#73
I have received a donation of $182.40 in honor of Mark Johnson.

Thanks to Scott for organizing the group buy and to all those who participated. The funds will be assigned to expenses involved in the upcoming forum migration, about which news will start to flow soon. Many thanks to all, and in particular Mark Johnson for his design which made it all happen.
 
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