Regulated B+ ?

[Delta Sigma]

Has anyone used a Maida-ish design to regulate B+ for a tube mic's power supply?

I want to be able to order a batch of PCBs and then transformers from a single source and be able to use them on any tube mic project. I played with some different B+ voltages and loads (100VDC - 220VDC) with passive filtering and with a Maida regulator. The Maida adds some parts cost, but it's easy to get 100 to 220 from the same transformer.

In other words, I could buy multiple transformers like this one, without knowing what project requirements would be:
https://sklep.toroidy.pl/en_US/p/TSTA-0015001-Mains-transformer-for-tubes/632

Same transformer and same PCB for multiple different projects with a few different components.

Started thinking of this after reading the @rock soderstrom thread with an already quite versatile PSU design:
https://groupdiy.com/threads/diy-pr...ps-like-preamps-buffers-or-microphones.84324/

Passive (for B+, regulate heater) might be the smartest way to go, but I do like the idea of using the same transformer for all future projects.

 

[Drosselmeier]

I ordered 20 transformers. They cost less than $15 each. B+ was made using a passive filtering. Suitable for M251 (+120V) and U67 (+230V) circuits.

 

[Delta Sigma]

View attachment 143343
I ordered 20 transformers. They cost less than $15 each. B+ was made using a passive filtering. Suitable for M251 (+120V) and U67 (+230V) circuits.

View attachment 143344

Where did you order them from?

 

[Drosselmeier]

Where did you order them from?

Russia
Rostov-on-Don city
"Tortrans" LLC
tel. +7(863)22066602

 

[rock soderstrom]

Passive (for B+, regulate heater) might be the smartest way to go, but I do like the idea of using the same transformer for all future projects.

Here is a thread about your topic with quite good info. Check the @Kingston PSU for an active regulated B+ version.

https://groupdiy.com/threads/regulated-b-solutions.71122/#post-906408

 

[gyraf]

The Polish company "Toroidy" mentioned/linked in OP are very competent people.

They are my main supplier of power transformers - their "Audio" type designs are among the quitest I've found.

You'll want to talk to Tomasz

/ Jakob E.

 

[Delta Sigma]

Here is a thread about your topic with quite good info. Check the @Kingston PSU for an active regulated B+ version.

https://groupdiy.com/threads/regulated-b-solutions.71122/#post-906408

Awesome. This is a lot simpler than the Maida, and I'd still achieve the wide range of loads from the same transformer. I really gotta start paying more attention to the Drawing Board.

 

[rock soderstrom]

Awesome. This is a lot simpler than the Maida, and I'd still achieve the wide range of loads from the same transformer. I really gotta start paying more attention to the Drawing Board.

I always wanted to build this circuit and merge it with my doubler heater-PSU linked above and then compare it directly in a microphone or preamp.

Here is my first draft for a PCB, what do you think? Sorry for the rough sketch. Diodes are UF4007, most electrolytic capacitors are 33uF/450V because I have a lot of them. I would like to install the LED as drawn, any cons?

How many dB ripple rejection would such a circuit have? We need Ian (@ruffrecords), I still can't work it out


R1,R2 = 1K for 10mA total current