Newbie working on Green Bean

[Petrucci]

Hello Everyone!
I am a newbie so go easy on me!
Am working on the Green Bean but confused as to the VB and VC on the schematic. What are these for ?

[Vallhagen]

VB and VC are "created" from your feeding 9VDC in the upper part of the schematic.

VC is your filtered 9VDC, and VB is half that voltage (9V divided by two=4.5V). It is common to split voltage like this to get a reference point in transistor or OP-amp stages.

Cheers

[RobA]

They are power supply voltages that are used in different parts of the circuit. Vb is the half supply reference voltage that the op amp needs since it is being operated in a single-supply configuration. Vc is pretty much +9V, but comes after the filter set up by R17 and C11.

You don't have to hook them up externally. They are generated in the power supply section. They are all hooked together on the PCB. On the schematic, they just make it easier to read because they eliminate bunches of connection that would be running all over the place. So, they are essentially just labels, but they do align with some electrical concepts of the circuit itself.  

Edit:
I was beaten to the punch, but figured you might find some of my long-windedness useful anyway.

[Petrucci]

Thank you for the responses. Since I am a newbie, I was thinking of breadboarding this first to get used to how things work but was also wondering if the VB  at the power stage would be connected to the VB in the circuit and the VC in the power stage to the circuit ...?

You guys are very helpful!

[RobA]

When I breadboard a circuit like this, I almost always end up using the same setup. I put the power section on the left side of my board and bring the power supply in there. I build the power section in a small area near the power supply input. I would then take VC to the top + power rail on my breadboard and VB to the bottom + power rail. The ground goes to the bottom - rail. I then hook the two ground rails together. (Just don't hook the two + rails together since they are now at different voltages.)

This arrangement makes it pretty easy to power the op amps and connect the VB points to where they go in the circuit. Notice in the power section where the 8 and 4 pins are connected. Those are the power pins from the op amp and the breadboard is pretty much set up now to hook the power up to them.

[Vallhagen]

Put it this way: anything called "vb" on The schematic is The same physical point. As roba said, its drawn this way for convenience in schematic reading. Hint: take your time and compare The schematic with The pcb layout, see if you can find Every component leg connected to vb and vc. Also: yea i gladly Encourage you to go on breadboarding, possibly The best way to learn this stuff:)...

Cheers!

[Petrucci]

You guys are the best! This explains it clearly!! Thank you

[Vallhagen]

Ha, RobA... We reply simultanously again:))

... Typing here on some tapatalking cellphone... And im not friend of The spellchecker Makin caps where they shant be!

[RobA]

Yeah! International tag-team DIY forum help.

[Petrucci]

Giggity!