Wish no one invented and used B+

[audiowize]

Ely Duttman’s highly valued design “El Cheapo”, as example (Sorry, Ely, thank you for a great design, sharing it, and being a good example). Why did you not show VDC on the “official schematic” instead of posting a bunch of transformers by name without ratings?

B+ PSU is Triad N77. I would call it 120V AC output into a voltage doubler is going to give you 300-340V DC.

The 6K27VF has a 125V secondary going through a bridge, so I would expect 130-170V DC out of that.

Prior to developing general intuition about this, you could download PSUD and run some quick simulations. If Eli listed the B+ as 337V DC and your power supply came out at 342V DC, then this will generate a forum question. When the next guy has 331V DC, then another forum question, and on, and on, and on.

 

[nigelwright7557]

B+ B- etc is handy for an amplifier where the rails are dependent on the speakers you are using. One voltage for 8 ohms and another voltage for 4 ohms.
Putting one voltage on the pcb would disagree with the manual which has two voltages.

 

[leadbelly]

Nobody seems to have challenged the OP on the subtext of his post. Why do want the schematic to just state voltage and current? There is this misconception among the less experienced that those 2 things are all that matter, so just toss out the PS design and roll your own. A good design will provide a PS design that has been optimized for much more performance specifications, and deviating from that will risk not meeting the performance specified. The tons of schematics floating around that are just advertised to "work" are maybe not as valuable as thorough, measured designs.

 

[stocktrader200]

I call the highest plate voltage B+. everything else is labelled V+ with voltage listed. I do SS primarily so the B+ is used simply because everyone else used B+ for tubes. I labeled V+ at the filter cap of 149v and labeled the voltage out at the regulator transistor emitter as 137v B+ for the 6922 preamp stage.

 

[dtproff]

This is neither a defense of the OP nor a condemnation of the way a lot of schematics were drawn. I will say if you are publishing schematics with no IP claims, then part attributes (resistance, capacitance, etc...) is the minimum schematic attributes as everything else can be back calculated.

 

[Lingwendil]

My usual way of doing things is "B+" for plate supply, "S+" for screen/G2 supply, "V-" for negative grid supply, "V+" for lower voltage positive supply (often a postive complement to the V-) and "B-" for any high voltage negative supply. Filaments usually get something like "F" if running AC, and "V+" if DC.

I usually state the voltage in parentheses next to the label if the PSU isn't drawn on the same page.

 

[lcsaszar]

If you don't know the nominal voltages of a design, why do you care about it? (the design, not the voltages)
You have to differentiate between commercial products (IPs) and DIY. In the first case some voltages might be indicated on the schematics to check if everything is in order. This is at the discretion of the manufacturer, and surely not intended to be copied.
In the case of DIY you either specify the BOM, or the voltages (and currents) at important points. Idle values of course; you turn it on first, test and smell, and drive only when all is OK.