A symbol I don't know

[primedynasty]

I am working on a circuit and came across a symbol that I am not familar with. It looks half an electrolytic cap, specifically the negative side. It appears numerous times. Anyone able to help?

[ianmgull]

Some schems use a solid rectangle as ground?

[punkin]

a picture please?

[primedynasty]

i unfortunately don't have my computer with me, but it is a solid rectangle that looks exactly like half of an electrolytic.  I thought ground as well but there is the traditional ground triangle on the schematic as well.  Also, on the Line In symbol there is a small representation of the solid rectangle.  with the ground of the line going to the symbol.  I will try and get picture if that isn't enough.

[primedynasty]

[aziltz]

its a reference voltage.

look midway down on the left where a separate circuit is used to create the BAR voltage from 8V, a cap, two resisters and ground.

[CGDARK]

its a reference voltage.

look midway down on the left where a separate circuit is used to create the BAR voltage from 8V, a cap, two resisters and ground.

No, it's not. It represents ground.

CG

[aziltz]

its a reference voltage.

look midway down on the left where a separate circuit is used to create the BAR voltage from 8V, a cap, two resisters and ground.

No, it's not. It represents ground.

CG

why would ground be on twice?  is this digital ground versus analog ground?  maybe you could explain that instead of just shooting it down.  if its digital ground, i'm not incorrect yet.

[CGDARK]

its a reference voltage.

look midway down on the left where a separate circuit is used to create the BAR voltage from 8V, a cap, two resisters and ground.

No, it's not. It represents ground.

CG

why would ground be on twice?  is this digital ground versus analog ground?  maybe you could explain that instead of just shooting it down.  if its digital ground, i'm not incorrect yet.

What you think is the digital ground symbol in fact is the reference voltage one. Just look above the transformer symbol. BTW, there's nothing digital in the circuit.

CG

[aziltz]

its a reference voltage.

look midway down on the left where a separate circuit is used to create the BAR voltage from 8V, a cap, two resisters and ground.

What you think is the digital ground symbol in fact is the reference voltage one. Just look above the transformer symbol. BTW, there's nothing digital in the circuit.

CG

that's exactly what i was referring to when i said "Reference voltage"

[CGDARK]

its a reference voltage.

look midway down on the left where a separate circuit is used to create the BAR voltage from 8V, a cap, two resisters and ground.

What you think is the digital ground symbol in fact is the reference voltage one. Just look above the transformer symbol. BTW, there's nothing digital in the circuit.

CG

that's exactly what i was referring to when i said "Reference voltage"

Yes, but he asked the other symbol not that one. To make things clear the triangular symbol = reference voltage (for this particular schematic only) and the rectangular one (like primedynasty said "It looks half an electrolytic cap, specifically the negative side.") is ground.

CG

[aziltz]

Yes, but he asked the other symbol not that one. To make things clear the triangular symbol = reference voltage (for this particular schematic only) and the rectangular one (like primedynasty said "It looks half an electrolytic cap, specifically the negative side.") is ground.

CG

i'm sorry but that seems completely backwards to me.  i give up helping.

[oldrocker]

Sounds like you guys are on the same page and don't realize it.  Some use the triangle as reference voltage others like when R.G. re-drew the John Hollis Omni-Drive schem he drew it opposite from John. (Pin 4 is ground)  You're both right IMHO.

[railhead]

Let's put it this way: in the schematic posted, the circled widgets are ground.

[oldrocker]

Right!

[CGDARK]

That's what I said!

CG

[frequencycentral]

LM3915 data sheet tells you everything.

[primedynasty]

All right well thank you so much for clearing that up. So another question, do I need to do anything with reference voltage or is it simply a place for diagnostics?  I really appreciate the help.

[slacker]

Not sure what you mean. If you're building it then you connect all the points will a black triangle together and all the points with a black bar together.

[aziltz]

its more for biasing and whatnot, i guess i can be used for diagnostics, but many its used to make 4.5V between the rails of 0 and 9V (for example)

on the side, i wish things were a bit more uniform, it would make learning a bit easier.