What is this circuit schematic symbol?

[justinrstout]

I'm working through this schematic: http://music.codydeschenes.com/wp-content/uploads/2013/05/JHS-Morning-Glory-Schematic.png

What is the broken line with a 4 and an 8 at the top left? I've looked up a bunch of circuit diagram references and couldn't find anything like this. Is it just a misprint? In that case, any idea what it actually could be?

[Scruffie]

Opamp power, pin 8 to 9V, 4 to Ground.

[samhay]

Edit - Scruffie beat me to it, so to elaborate, this is how Eagle (and probably other) circuit software denote the power supply to each IC.

[justinrstout]

Thanks! 

[PRR]

> What is the ... with a 4 and an 8

The morning after the poker night you find two cards on the floor. A 4 and a 8.

Look around. IC1 has 1-2-3 on the A side, 5-6-7 on the B side.

I don't see any other naked (no letter) numbers.

IC1 is known to be an 8-leg device.

You found 8 cards which seem to fit IC1's hand. An 8-card Straight. Or in electrical terms, a Full Set (of 8 pin connections).

OK, I'm mixing-up my body parts (hands, legs?) and my card-conventions. And I admit it was not instantly obvious the first time I saw this notation shortcut.

[ElectricDruid]

Edit - Scruffie beat me to it, so to elaborate, this is how Eagle (and probably other) circuit software denote the power supply to each IC.

I prefer the ones that show a little box representing the IC, helpfully labelled underneath! The fact this question gets posted shows that the Eagle way isn't actually that clear or obvious.

T.

[samhay]

>I prefer ...

It's not perfect, but for op-amps Eagles approach can work pretty well. You can place the symbol on top of the op-amp symbol (e.g. here) if you want to be explicit, but it will thow up errors. For circuits with multiple ICs, which almost certainly all use the same power supply, this can get messy, so tucking them all away in a corner (or not showing them) is my preference.

Conversely, drawing an IC as e.g. an 8 pin box is not great unless you show the pin assignment as part of a block diagram (e.g. here) as it saves you having to dig out the data sheet to find the pin assignment.

[ElectricDruid]

I've got no problem with using a separate "part" for the power supply pins for a given component. After all, you don't want to have to lay out both op-amps in a TL072 with only one 8-pin box - that'd be awful. I hate those single op-amp components with power pins and offset adjust wires sticking out all over them - ugh!

I just think the power supply pins symbol could do better than just be some bare wires that don't go anywhere and aren't labelled at all. Diptrace uses a little box on most components, and labels it underneath (e.g a dual op-amp will have the two amp symbols IC1.1 and IC1.2 and a power pins symbol IC1.3 - you choose if you want the type/value labelled too)

T.