Discussion in 'General Electronics Chat' started by Mathematics!, Nov 16, 2008.

1. ### Mathematics! Thread Starter Senior Member

Jul 21, 2008
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Question 1 Last breadboard picture on page

Why is this a short?
Is it because the column holes are all connected together so the electricity travels in the path of least resistance. By passing going thru the component.
Question 2
I am having trouble understanding how electricity flows in a solderless breadboard?Is the 5 holes in a column's always the same voltage? (Are they wired together)
If that is the case then you should never put 2 ends of the same piece in the same column?
But if this is the case how do you put components in parrallel ?
I believe the top 2 rows get the same voltage. (i.e the wholes are all connected together behind the scenes.)
Thanks for any clarity.
Sorry for the stupid question but it is holding me back from understanding how to create circuits in a solderless breadboard.

Last edited: Nov 16, 2008

Apr 5, 2008
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Hello,

Here is a short description how a breadboard is connected internaly.
See the PDF.
I hope this makes things a little bit more clear.

Greetings,
Bertus

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3. ### Mathematics! Thread Starter Senior Member

Jul 21, 2008
1,022
4
So going by this you should never put a led , resistor ,...components etc both of it's ends in the same column?
And if you put one end of a resistor in a column and one end of a led in the same column. Both the components are going to recieve the same voltage , current ,..etc.
The way you can drop voltage over a led is
col1 , col2 , col3
r1------- r1
*****col2 col 3
*****Led led ends

* star means nothing in hole and is used for aligning the stuff in my post.

Last edited: Nov 16, 2008

Apr 5, 2008
15,650
2,348
Hello,

Have you also seen the long strips along the side of the board?
At some breadboards there are even colored line along the long strips.
These can be used as powerstrips , + and GND for instance.
You can put a led anode to the + strip , kathode to col 1 ,
resistor between col 1 and col 2,
and col 2 can go to one side of a switch ,
the other side of the switch can go to the GND strip.

Greetings,
Bertus

Mar 24, 2008
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6. ### hobbyist Distinguished Member

Aug 10, 2008
764
56
Another way to check the breadboard, if you have no diagram showing the connections, is to use a multimeter with a continuity checker and probe the holes,
because some bread boards inline strips may or may not all be connected down the whole board. (power strips) one board has a brerak in the middle while another has continuity all the way down the strip.

7. ### Mathematics! Thread Starter Senior Member

Jul 21, 2008
1,022
4
Ok , I get that the top 2 rows are for power and ground.
And each hole in those row's are connected behind the sense.

But I am wondering why you cann't stick both ends of a led in the same column.

Say the first A-F column for insistance.

Why does this cause the led to not light up and not have a voltage across it. (I think I know why just need some assurance )

And I am having a hard time see how you can connect stuff in parellel.
Your timer 555 example was exactly one of my problems. It shows
a resistor between to other components going to the chip.
_power
|
resistor - chip
|
resistor - chip
|
capacitor
|
ground

But if all the holes in a column are the same voltage then you have to use only one hole for each component you can never put 2 legs of a component in the same column?

Do you have to always use 2 columns for every component (excluding the top 2 rows)? So a column is like 1 nodes.

Because in solder breadboards you can chose what is connected to what.
In solderless breadboards their is some pre connections behind the sense.

This is why I am getting confused on building some of these circuits.
They look easy and are easy on solder breadboards but when using solderless breadboards (protype boards , test boards whatever you call them) I am consistantly screwing up the circuit by either putting a resistor in front of a led but both legs in the same column.

Like
col 1
resistor ( both legs in col1)
|
led

and think the resistor will be voltage drop but it seems not the case.
I think I know why but need a little assurance.