What does the term B+ mean relating to a vacuum tube circuit

[@raymondmenard5444]

Finally ! Someone who clearly explains what B+ voltage is and where the name comes from. Thank's for sharing that. Newbie here trying to learn before i dive into restoring 2, 1937 superhet sets i have. Be well, God bless.

[@1959Berre]

That's what our teachers used to call "an in depth" explanation. Well done Mark.

[@peteruren4086]

Thank you so much. First time someone explains B+ so understandably

[@nighttrain022]

Mark here too, Dinamo said it. for a newbie to learning electronics, this is nice to be shown where the B+ term comes from. For those who posted about where it seems he reversed anode and cathode, maybe Mark just mis-spoke and forgot to edit the correction in. The basic working principle of a vacuum tube is a phenomenon called thermionic emission. It works like this: you heat up a metal, and the thermal energy knocks some electrons loose. ... When the cathode is heated, and a positive voltage is applied to the anode, electrons can flow from the cathode to the anode.

[@acestudioscouk-Ace-G0ACE]

I had the same question and was glad to find your video which explains it so well, thanks Mark. Being a Brit, I knew "HT" but didn't know it was the same as B+. 👍

[@anthonykay5100]

And another pin drop. Great little tutorial giving us another piece of the puzzle including a bit of history. Very much enjoy working my way through the archive of great material while waiting for the next greatly anticipated 300B instalment. Thank you Mark

[@Monaco-BuilditFixitDriveitEver]

Yes! I have had the same question. I love the battery pictures. Thank you for the explanation.

[@billinrio]

Finally, a clear explanation about a term that I hear all the time, and never understood why it has that name!

Thank you. I've searched and finally found a guy who explains this with a proper schematic and explanation This is a huge help. Nice work.

[@jeffcotton526]

Go to Uncle Doug's channel, he explains it much better: kzbin.info/www/bejne/b2GUmpSGi7utj5I

[@alvarogeorg]

@@jeffcotton526 OK, I just saw it. I only disagree when Uncle Doug's says that the vaccum made by the B+ on the anode atracts the electrons...

[@jeffcotton526]

@@alvarogeorg Yeah it's a little fuzzy on that one. I believe he meant the electron attraction created by the B+ voltage on the plate. I guess it could be termed an "electron vacuum".... Between Mr. Carlson's Lab and Uncle Doug I have received most of the answers to many perplexing electronic questions I've had in the past. I just joined Paul's Patreon Page to learn more.

[@alvarogeorg]

@@jeffcotton526 I have just saw the first part of that and I think that, in fact, he was making an analogy with a vaccum cleaner "sucking" the electrons.

[@UncleDoug]

I always thought that the amplified signal on the plate was out of phase with the music signal input to the grid. In your diagram, they are in phase. Was this just for simplification?

[@Blueglow]

Indeed, probably should have drawn correctly

[@paulstratton5147]

You have a very clear way of expaining things Mark, very many thanks..

[@jeffcotton526]

Electrons in a vacuum tube always flow from the cathode to the anode (plate). Since the plate has a higher positive voltage versus the cathode the attraction is very strong for the electrons being boiled off of the cathode. The cathode is negatively charged with a huge excess of electrons which are seeking the plate (excess of positive charge) and therefore are attracted to the plate. Uncle Doug's KZbin channel has a more in-depth discussion of this using some good analogies to simplify the process. kzbin.info/www/bejne/b2GUmpSGi7utj5I How Tube Amplifiers Work

[@budandbean1]

I have to agree wholeheartedly with other, you are an amazing instructor. I take it for granted that anode voltage is B+ typically but I’ve really never understood exactly why although I’ve seen this same presentation. Must have zoned out reading it for myself or listening to someone else drone on about it or go over it to fast, etc. I’ve only been subbed to your channel for six months or so and I did it because I thought you might be explaining more about guitar amplifiers but I’ve stayed because of the way you talk and teach. You have a soft spoken way about you that, at least in my case, helps me focus in and really understand what you are talking about. Thank you for your time and help you provide to everyone. -Buddy

[@CraftAero]

[facepalm] Been playing around with tube amps / devices for quite some time and just accepted B+ as "what they call it". I figured it was a legacy type term but never dug into the origin. Thank you muchly for this piece of trivia. I've been subscribed here for quite a while but I rarely comment (on any channel). I would be (and have been) remiss not to thank you for your excellent content. I recently came across several NOS 6L6G Westinghouse Marconi tubes (and a bunch of NOS 50L6GTs) that I'll be using to build some HiFi amps with. Your channel has been very informative and inspirational. You have a great way of getting solid information across without dimming your language down or talking over the heads of your viewers. Your channel and a few others like it have convinced me to record and share my amp builds this summer. I'm going to start with some high voltage play (flybacks & MOTs) with various drivers and capacitors to hone my video, editing and presentation skills. I will certainly remember to give you, and a handfull of others, credit for inspiring me to create and share my content.

[@queuerious]

Many thanks. A neat and concise explanation of precisely the question I asked myself. Thank you!

[@Rudofaux]

Thermionic electron emission happens at the cathode. Why would the anode be emitting electrons when they are positively charged?

[@jimtanis67601]

Electrons are boiled off the cathode by heating it with the filament. Electrons, because of their charge, are attracted to a positive source, the plate, so flow through the grid to the plate. The grid modulates this flow.

[@albundy1956]

Excellent explanation, U are a good teacher. Greetings from Sweden.

[@20thcenturyboy85]

Most AMAZING videos explaining this topic!

[@johnnytheg]

Fantastic explanation of something I was always curious about.

[@johnbravo7542]

Great video Mark,as I had heard the term "HT" in forums,now I know what it means high tension

[@briankays2635]

Great explanation! Simple - no bull. Thanks!

[@ross3818]

The A and B batteries were utilized for Fleming's diode, before triodes. The C battery was added in order to provide the negative bias a triode's control grid requires.

[@4hammonds672]

very well explained and very well understood, all of your videos are awesome, the building of the KT88 amp and the ""how to understand tube amp schematics. thanks Mark

[@truthreigns7]

Thank you very much. You have cleared up allot in explaining this to me.

[@lambertax]

Who new that? Greatest explanation ever! Thanks 🙏

[@josephwarren849]

Another great video, that was very interesting I’ve been wondering what B+ meant for a long time. Thanks Joe

[@marklough6218]

Cheers for taking the time - highly informative.

[@KameraShy]

I had wondered about that for the longest time. Now it makes sense! Thanks!

[@thilokaal]

I always wondered ever since what B+ meant. Thx very much. Greetz from germany:-)

[@1DShoe]

Great explanation! Made it real easy for this dummy to understand :)

[@bob4analog]

1:05 I always thought electrons flow from the cathode to the plate. Did I get it wrong?

[@silasfatchett7380]

No.

[@hijmestoffels5171]

I had exactly the same question. Now I understand. Thank you!

[@GaRbAllZ]

Always thought electrons flow from cathode to plate....

[@Blueglow]

Technically you are correct. Electron flow vs. conventional current flow theory discussion, a classic 80 year old debate.

[@patrickoconnell3896]

I enjoy your videos. I was taught electron flow when learning electronics.

[@dw8840]

That's what I was taught too, electrons flow against the arrow on a schematic for a diode. (unless it's a Zener diode, then it flows into the "cats" mouth and out his anode {as taught to me by my electronics instructor})

[@larryak0z672]

@@Blueglow I use conventional flow. I find it easier to understand although I do both.

[@davidcuthbertson9840]

Your right - they "electrons" flow from the cathode to the anode. The difference is the current (conventional) flow is considered to flow from + - and electron flow flows from - to +

[@swinde]

When I learned tube theory, it was stated that the heater boiled electrons from the cathode which were attracted by the plate and the current flowed from cathode to anode. (Negative to positive). But it turned out that the math was easier if the flow was from positive to negative. I tend to believe that the former is correct though because of the description of the free electrons being emitted from the cathode and then attracted to the plate.

[@billbraskey5349]

Great informative video and very well explained. Thank you!

[@jjiacobucci]

Thank you ! Very clear discussion !

[@williamland3772]

Wait, electrons flow from the plate to the cathode? Isn't the other way around?

[@williamland3772]

There is a difference in conventional current flow (which is really hole flow) and the actual flow of electrons. To say that electrons flow from the plate to the cathode is just not correct terminology in my opinion. I would be good with the current flows from plate to cathode, as it is the convention that we use in schematics. Not knocking your video, it was great, I just think that certain terminologies that people are using, lead to most people's confusion.

[@SargentRay]

Had the same question, thank's for this great answer and schematics, it does make things very clear now.

[@jasoncollier214]

Straight simple... THANK YOU!

[@kane100574]

Great explanation! I love your channel, man. I hope you keep it up!

[@donlamontagne7606]

This is an excellent video, but it brings up a question of what wire gauge should I use for these high voltages

[@DaveMcAnulty]

Look at your wire, it's usually printed on it.

[@donlamontagne7606]

I know but, should I use 20 gauge throughout or heavier for B+

[@tonyrink9999]

Excellent explanation

[@kwacz]

Great video thanks!! Question though. I have a radio with a full wave selenium rectifier. In checking the output of this rectifier, how do I determine if the voltage (assume B+) is correct. I cant find a schematic for this no name radio anywhere. Do I go off the vacuum tube datasheet for maximum plate voltage and stay just under this? or is there another way to determine this?

[@sc0or]

Is 33uF too much for a tube rectifier? I read that 20uF can be supposed as a max capacitance. Besides, these days a transistor stabilizer is cheaper than a space inside a case occupied with a tube rectifier and additional 20-30 volts in a transformer ))

[@paulperriman9144]

Hi. Does not the electrons flow from Negative to positive and current flows from positive to negative? in your video it was electrons flow from plate (anode) to cathode (k) im a bit confused now..

[@Finom1]

Where do you buy your 630vdc caps? Great video.Now how to add pots to adjust bias on a 4 tube Push/Pull amp?

[@whynotme5926]

Good explanation.Can you put a dropping resistor on the plate of the output tube 6v6 like you do on the 12ax7. Maybe from the lead off the output transformer to the plate of the 6v6 and why you can or why you can't. Thank you for any help. I have asked this question over and over and I am hoping someone will touch on this. And another thing-What determines what value electrolytics you use in the power section. I know you can go to other schematics and see what someone used but it would be great to know how to figure it out on paper.Again, thanks for any help.

[@parachuteman4]

Did deforest add the grid? Or did Edwin Armstrong? According to empire of the air DeForest really didn't even know what to do with the vacuum tube. It was Armstrong who actually made it a practical usable item. Empire of the air: the men who made radio. Great documentary.

[@frank-ts1yr]

Hi Mark, i got a similar question somewhat. I assume a guitar signal has positive and negative cycles, my question is if the anode is positive, how does the anode turn negative to simulate the guitar negative? Please help. Frank

[@silasfatchett7380]

When the tube is idling with no signal applied to the grid a certain amount of current (the quiescent current) is flowing in the tube. When a signal applied to the grid goes positive the flow of current electrons increases above the quiescent current, and when the signal goes negative the current decreases below the quiescent current. This varying current flows in the plate/anode resistor causing the voltage across it and therefore the voltage at the anode to vary in sympathy with the input signal. The anode never goes negative, it goes more and less positive.

[@frank-ts1yr]

@@silasfatchett7380 thanks Silas, let me digest that

[@vidlover81]

Mark, this video helped a lot, thanks.

[@Torpengpogi]

hi mark, based on the schematics of your B+, the B++ was reduced by a 100 volts using 8.2K ohms, and the B+++ used a 10K ohms but only reduced 50 volts? how did this happenned? thanks from Canada.......................

[@silasfatchett7380]

The voltage drop is smaller because the 10k is passing less current that the 8.2k. With 100V dropped across an 8.2k resistor, (I = V / R) 100 / 8200 = 0.0122A or 12.2mA must be flowing. This current is the sum of the current being supplied by both B++ and B+++ . If there is a voltage drop of 50V across a 10k resistor it must be passing 50 / 10,000 = 0.005A or 5mA which is being supplied by B+++ so the current being supplied by B++ must be 12.2 - 5 = 7.2mA.

[@omarcusihuaman4261]

why is necessary to use High voltage?

[@TonyButchT]

Thank you for this explanation! What does the B- (minus) mean and where can it be found? Chassis ground and B- different? (They use different symbols) I am troubleshooting an AA5 radio, want to check voltages, need to measure to B-. Thanks again! (using isolation transformer!)

[@dannyyorri2345]

Thank you for that info very useful.

[@iblesbosuok]

807, 1625, 6146 are real nice valves

[@adamp185]

Thank you Mr Mark!

[@rayislooking2]

Great Explanation Thanks

[@jwingo7257]

Every field has its terminology designed to confuse the uninitiated...medical doctors, mechanics, lawyers and accountants. Which “whatchamacallit” do you connect to the “thingamajig”?

[@texasblues1]

Great video, cheers brother!

[@dougms9790]

No B- voltage?

[@cartematt]

I always wondered too, thanks.

[@joepublic4069]

Nice. Good video.

[@11thgenerationcorolla57]

I need to find that b+ in my car! ☹️ i really need help!

[@linandy1]

Very interesting !

[@thematey3592]

Thank you. Much appreciated....

[@marvinbrando5408]

Great answer.

[@tuohuangzhe3700]

非常好讲解!

[@tgirard123]

God I love KZbin. I'm just getting into tubes and was wondering that myself.

[@MarkSchuster-ym3iy]

Thank you. Very good

[@anthonyselby8337]

Thank you 😊

[@james5553]

Brilliant - thank you :)

[@henryburt72]

Thank you!

[@weechitamex]

THANK YOU SIR .

[@MrMrjauregui]

Thank you!!!!!

[@NotGonnaSayFO]

I FINALLY GET IT!!!

[@garyk.8674]

Thank You

[@edwardebel1847]

Thanks!

[@duality4y]

"what it does is slow down or stop the flow of electrons from the plate to the cathode" wrong the cathode emits electrons and the plate collects them

[@jatza07]

Thank you :)

[@dw8840]

I had a feeling B+ meant battery.

[@jcmcovers4487]

🤯🙂🎯👍🏼

[@larryak0z672]

I wish someone would say we are going to say just anode or just plate so we don't have to explain they are the same every time. Okay, I will say it is an anode. All agree? lol

[@silasfatchett7380]

People in North America would tend to disagree.

[@PeterWalkerHP16c]

2:25 Thank me later.