Complete and utter beginner question about Dual Timer Part.

Hi guys,

Tonight I started looking into electronics as I want to do engineering at uni and thought it would be sensible to get some basic knowledge.
I found a beginner project to start on, the "atari punk console".
I'm using this schematics diagram

**broken link removed**

I understand the resistor and capacitor symbols and I know the square things are the dual timers but I'm having difficulty following the rest seen as I'm following no guide and this is literally all I'm working from with a tiny bit of prior knowledge from GCSE physics :-D

Could someone explain what the circles with '+' signs in them are. I thought they were batteries and the +9v suggests this too but seen as there's 5 of these icons on the diagram I thought it might point elsewhere. Also what is the GND symbol? I think it means the ground wire but I don't see where you'd ground it...
Another thing, the timer part has a part number "LM556N" but I can't find anywhere to buy it and instead I've found "NE556N". Would there be any difference between these?

Again, I'm sorry this is such a beginner thread. If there's an article or website someone could recommend to get started and familiarised with stuff that'd be great!

Thanks

Turnitdown said:

Could someone explain what the circles with '+' signs in them are. I thought they were batteries and the +9v suggests this too but seen as there's 5 of these icons on the diagram I thought it might point elsewhere. Also what is the GND symbol? I think it means the ground wire but I don't see where you'd ground it...

Click to expand...

You thought correct! ;-)
+9V and ground belongs to the power supply. If you are going to supply this circuit from battery then it is battery. If it is DC voltage coming from another circuit, then this should be it. If the supply comes from a power supply unit, then adjust it to +9VDC. You see 5 of them because 5 points of this circuit needs to be connected to +9V. Instead of having a wire in the schematic going from here to there and get you confused by trying to follow, it is just marked as 9V.

As for ground, it is just a reference. Try to think of it as 0V.

If you have a 9V battery, then +9V would be the '+' of the battery and gnd would be the '-'.

PS: Welcome to the world of electronics! :-D

Hope this helps,
Alexandros

alexxx said:

You thought correct! ;-)
+9V and ground belongs to the power supply. If you are going to supply this circuit from battery then it is battery. If it is DC voltage coming from another circuit, then this should be it. If the supply comes from a power supply unit, then adjust it to +9VDC. You see 5 of them because 5 points of this circuit needs to be connected to +9V. Instead of having a wire in the schematic going from here to there and get you confused by trying to follow, it is just marked as 9V.

As for ground, it is just a reference. Try to think of it as 0V.

If you have a 9V battery, then +9V would be the '+' of the battery and gnd would be the '-'.

PS: Welcome to the world of electronics! :-D

Hope this helps,
Alexandros

Click to expand...

So where is the Ground wire connected to? Nothing?
Also, could you explain the resistor with a loop cycle please

Thanks you by the way,

Turnitdown said:

So where is the Ground wire connected to? Nothing?

Click to expand...

I already answered in the first post :smile:

If you have a 9V battery, then +9V would be the '+' of the battery and gnd would be the '-'.

Click to expand...

Turnitdown said:

Also, could you explain the resistor with a loop cycle please

Click to expand...

This part is called "potentiometer" and it is a variable resistor. In this circuit it is connected as rheostat. Please take a look at the below reference:
https://www.edaboard.com/threads/235256/

---------- Post added at 20:46 ---------- Previous post was at 20:44 ----------

Turnitdown said:

Another thing, the timer part has a part number "LM556N" but I can't find anywhere to buy it and instead I've found "NE556N". Would there be any difference between these?

Click to expand...

I believe it is the same:
LM556 pdf, LM556 description, LM556 datasheets, LM556 view ::: ALLDATASHEET :::

alexxx said:

I already answered in the first post :smile:




This part is called "potentiometer" and it is a variable resistor. In this circuit it is connected as rheostat. Please take a look at the below reference:
https://www.edaboard.com/threads/235256/

Click to expand...

Oh sorry, I misread the '-' completely!
Thanks for the link